FUNDAMENTALS OF INTERNET 33. 1 INTRODUCTION The latest buzzword in computer world is ‘Internet’. It has taken the entire world by surprise with its cutting edge technology to connect people and computers throughout the world. Using Internet, organizations all over the world can exchange data, people can communicate with each other in a faster and effective way, and researchers can gather information in their respective area of research.
With help of video conferencing over Internet, it has become possible that people can even see each other while communicating and it is possible by video conferencing over Internet. Even one can do all his shopping sitting back at home. He does not bother to go to the crowded market place. Slowly shopkeepers are also opting for electronic commerce, which provides them greater reach and fastest way to do business over Internet.
Don’t get surprised, if you come to know that the Paan walla in your locality has started selling his paan over Internet. 33. 2 OBJECTIVES At the end of this lesson you would be able to: ? define Internet? understand and explain various terminology used in Internet? use various services provided by Internet? search for information over Internet? enjoy Internet surfing? send E-mail and do FTP 33. 3 INTERNET- THE HISTORY? In 1969, the U. S. Defence Department funded a project to develop a network, which can withstand the bombing.
Basically the idea was to develop a very secure network which can work even after a nuclear attack. This project was known as ARPANET. The proposed network was not supposed to have a central control-which would be an obvious target. Ten years of research brought Local Area Ethernet Networks (LANs) and workstations were developed to get connected to LAN. These workstations and LANs were then connected to the ARPANET. For next decade the ARPANET grew and its decentralized features helped its rapid expansion.
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Computers connected to ARPANET used a standard or rule to communicate with each other. This standard used by ARPANET is known as NCP (National Control Protocol).
Protocol is a network term used to indicate the standard used by a network for communication. But the passing time and rapid change in information technology suppressed NCP and brought TCP/IP (Transmission Control Protocol/Internet Protocol) in to the world of networking. TCP “converts messages into streams of packets at the source, and they are reassembled back into messages at the destination. IP handles the dispatch of these packets.
It handles the addressing, and makes sure that a packet reaches its destination through multiple nodes and even across multiple networks with multiple standards. This flexibility of TCP/IP to handle multiple networks with multiple protocols encourages other networks to get connected to ARPANET. Slowly the ARPANET became a massive network of networks and now it is known as ‘Internet’. Internet is termed by some people as the world of largest democracy with no government.
It has no state of head to control it. Why do people want to get connected to Internet? May be because of freedom it provides. The Internet is a rare example of a large democracy with no state of head, no official censors, no bosses, no board of directors. Nobody controls the Internet and in principle, any computer can speak to any other computer, as long as it obeys the technical rules of the TCP/IP protocol.
This freedom of Internet helped it to move out of its original base in military and research institutions, into elementary and high schools, colleges, public libraries, commercial sectors even into the shop of a vegetable vendor. 33. 4 SERVICES OF INTERNET – E-mail, FTP, Telnet, WWW But what does one do with the Internet? May be four things, basically: mail, discussion groups, long-distance computing, and file transfers. Internet mail is (e-mail or electronic mail), much faster as compared to normal postal mail. One can also send software and certain forms of compressed digital image as an attachment.
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News groups or discussion groups facilitate Internet user to join for various kinds of debate, discussion and new sharing. Long-distance computing was an original inspiration for development of ARPANET and does still provide a very useful service on Internet. Programmers can maintain accounts on distant, powerful computers, execute programs. File transfers service allows Internet users to access remote machines and retrieve programs, data or text. (a) E-Mail (Electronic Mail) E-mail or Electronic mail is a paperless method of sending messages, notes or letters from one person to another or even many people at the same time via the Internet.
E-mail is very fast compared to the normal post. E-mail messages usually take only few seconds to arrive at their destination. One can send messages anytime of the day or night and it will get delivered immediately. You need not to wait for the post office to open and you don’t have to get worried about holidays. It works 24 hours a day, seven days a week. What’s more, the copy of the message you have sent will be available whenever you want to look at it – even in the middle of the night.
You have the privilege of sending something extra even such as a file, graphics, images etc. along with your e-mail. The biggest advantage to using e-mail is that it is cheap, especially when sending messages to other states or countries and at the same time it can be delivered to a number of people around the world. Although e-mail is faster and cheaper, it has many of the components of regular mail. It allows you to compose note, get the address of the recipient and send it. Once the mail is received and read, it can be forwarded, replied.
One can even store it for later use, or delete. In e-mail even the sender can request for delivery receipt and read receipt from the recipient. (i) Features of E-mail: ? One-to-one or one-to-many communications? Instant communications? Physical presence of recipient is not required? Most inexpensive mail service, 24-hours a day and seven days a week? Encourages informal communication (ii) Components of an E-mail Address As in the case of normal mail system, e-mail is also based upon the concept of a recipient address. The email address provides all of the information required to get a message to the recipient from anywhere in the world. Consider the e-mail ID In the example above, “john” is the local part, which is the name of a mailbox on the destination computer, where finally the mail will be delivered. Hotmail is the mailserver where the mailbox “john” exists, .
... computer file directories. This service is linked across the Internet to allow other users to browse files. File Transfer Protocol (FTP) allows users to transfer computer files ... be sent from one computer to one or more other computers. Internet e-mail standards have become the ... to another computer from a remote location. Simple Network Management Protocol (SNMP) allows almost any Internet object to ...
com is the type of organisation on net, which is hosting the mail server. There are six main categories; com Commercial institutions or organization edu Educational institutions gov Government site mil Military site net Gateways and administrative hosts org Private organizations (b) FTP (File Transfer Protocol) File Transfer Protocol, is an Internet utility software used to upload and download files. It gives access to directories or folders on remote computers and allows software, data and text files to be transferred between different kinds of computers. FTP works on the basis of same principle as that of Client/Server.
One can easily Login to the FTP site with the username anonymous and e-mail address as password. The basic objectives of FTP are? to give flexibility and promote sharing of computer programs, files and data? to transfer data reliably and more efficiently over network? to encourage implicit or indirect use of remote computers using Internet? to shield a user from variations in file storage systems among hosts. Fig. 33. 1 The basic steps in an FTP session are: ? Start up your FTP client; by typing ftp on your system’s command line/’C>’ prompt (or, if you are in a Windows, double-click on the FTP icon).
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? Give the FTP client an address to connect to.
This is the FTP server address to which the FTP client will get connected? Identify yourself to the FTP remote site by giving the Login Name? Give the remote site a password? Remote site will verify the Login Name/Password to allow the FTP client to access its files? Look directory for files in FTP server? Change Directories if required? Set the transfer mode (optional); ? Get the file (s) you want; and? Quit. (c) Telnet (Remote Computing) Telnet or remote computing is telecommunication utility software, which uses available telecommunication facility and allows you to become a user on a remote computer. Once you gain access to the remote computer, you can use it for the intended purpose. The TELNET works in a very step by step procedure. The commands typed on the client computer are sent to the local Internet Service Provider (ISP), and then from the ISP to the remote computer that you have gained access. Most of the ISP provides facility to TELNET into your own account from another city and check your e-mail while you are travelling or away on business.
The followings steps are required for a TELNET session? Start up the TELNET program; ? Give the TELNET program an address to connect to (some really nifty TELNET packages allow you to combine steps 1 and 2 into one simple step! ); ? Make a note of what the “escape character” is; ? Log in to the remote computer; ? Set the “terminal emulation;” ? Play around on the remote computer; and? Quit. IN-TEXT QUESTION 33. 1 1. Fill in the blanks.
(a) is a network term used to indicate the standard used by a network for communication. (b) File Transfer Protocol, is a software used to upload and download files. (c) Hotmail is the. (d) The commands typed on the client computer are sent to the. (e) The basic objective of FTP are to give flexibility and promote sharing of files and. 33.
5 WORLD WIDE WEB (WWW) WWW is the acronym for the World Wide Web. It is also commonly known as ‘The Web’. The WWW is hypertext based information retrieval tool. One can easily surf the Web by jumping from one document to another using the links in those documents. These documents can be in many formats, such as text, graphics, animation, sound and latest is video. They may also be a combination of all these.
... Make sure you can access the World Wide Web through your Internet account before you attempt to publish a Web page. You " ll need ... ask you for the Dial-Up Networking connection for accessing the account. Choose your connection (you should already be connected to this ... but still encounter problems during Setup, check that your computer has the minimum requirements necessary to install Creative Writer 2 ...
All the information on Internet are presented to the user as a document or more popularly known as Web Page. All these Web Pages are link to each other or even to section within a Web Page. And these links are known as Hyper Links. The tool used to view these Web Pages on Internet is known as Internet browser or simply browser. It is a software program specifically developed to extract information on user request from the Internet and present them as a web page to the viewer. There are several browsers available in the market.
However the most popular are Internet Explorer from Microsoft and Netscape from Netscape Inc. The process of using browser to view information on Internet is known as Browsing or Surfing. Fig. 33. 2 (a) Internet Address Just like every house, every office, every location has an address, every page on the Internet has a unique address. This address is used get the web page for user from Internet.
Just as the address of a house or office is known as its postal address, the address on the Internet is known as URL (Uniform Resource Locator).
A typical Internet address or URL would look like; web > The URL locates a particular web Page, among all the computers connected to the Internet. The URL contains the components that specify the protocol, server, and pathname of an item. Let us examine the URL given above (web).
The protocol is followed by a colon ( ), the server is preceded by two slashes (// web), and each segment of the pathname is preceded by a single slash (/computers / internet /url. htm).
A protocol is set of rules that tells the computer know how to interpret the information at that address. Fig. 33. 3 The first component, the protocol, defines the manner for interpreting computer information. Many Internet pages use HTTP (HyperText Transfer Protocol).
Other common Internet protocols that one might come across are FTP (File Transfer Protocol), NEWS (Usenet news groups protocol), and GOPHER (an alternative transfer protocol).
... occur several different ways. Web sites such as www.register.com offer web page space on the Internet for the fairly inexpensive price ... in a clean and professional way. Bright colors, blinking text, large images, and attention getting backgrounds often take away ... device that blocks unauthorized access to an organizations local area network that is exposed to the Internet. What that mean is ...
Gopher protocol is mostly out of date now. The second component, the server (web), identifies the computer system that stores the information you seek and is always preceded by two slashes. A server is a computer that has information stored on it and sends it to the client, when a request is made. Each server on the Internet has a unique address name whose text refers to the organization maintaining the server.
The last component (/computers / internet /), defines the path within the Server where the requested item (url. htm) will be found. Most of the Web pages will have. htm or. html as their secondary or extension name. (b) How to get connected to Internet There are various type of connectivity to get hook on to Internet.
They all can be broadly classified into following category. (i) Gateway Access Gateway Access is also known as Level-One connection. It is the access to the Internet from a network, which is not on the Internet. The gateway allows the two different types of networks to “talk” to each other. But the users of the Gateway Internet have limited access to the Internet. They might not be able to use all the tools available on Internet.
The local Internet Service Provider (ISP) normally defines this limitation. Good example of network with Level One connectivity within India is that of VSNL (Vides h San char Nigam Limited).
All access to Internet from India are through VSNL gateway. Fig. 33. 4 (ii) Dial-up Connection ‘Dial-up’ connection is also known as Level Two connection.
This provides connection to Internet through a dial-up terminal connection. The computer, which provides Internet access is known as ‘Host’ and the computer that receives the access, is ‘Client’ or ‘Terminal’. The client computer uses modem to access a “host” and acts as if it is a terminal directly connected to that host. So this type of connection is also known as ‘Remote Modem Access’ connection.
And the host to which the client gets connected is actually connected to the Internet by a full time connection (See Leased Connection).
Fig. 33. 5 In dial-up connection to Internet, Host carries all the command that are typed on a client machine and forward them to Internet. It also receives the data or information from the Internet on behalf of the ‘Client’ and passes it to them. The client computer acts as a ‘dumb’ terminal connected to remote host.
This type of connection can further be divided into two categories. (iii) Shell Connection In this type of Internet Connection, the user will get only textual matter of a Web Page. This connection does not support Graphics display. However the user will be able to surf the Internet, do FTP, receive mail. Shell Accounts were the only type of Internet access available for many years before the Internet entered in to the world of graphics and became more users friendly.
(iv) TCP/IP Connection Today’s graphical World Wide Web browsers provide easier access with multimedia sound and pictures. The major difference between Shell and TCP/IP account is that, Shell account can only display text and does not support graphics display, whereas TCP/IP can display both. Hence it is more popular Internet connection. Shell accounts are slowly phasing out from the Internet scenario. To access any of these dial-up accounts you need the followings; ? Computer? Modem? Telephone Connection? Shell or TCP/IP account from the ISP? Internet client software such as Internet browser. (v) Leased Connection Leased connection is also known as direct Internet access or Level Three connection.
It is the secure, dedicated and most expensive, level of Internet connection. With leased connection, your computer is dedicated ly and directly connected to the Internet using high-speed transmission lines. It is on-line twenty-four hours a day, seven days a week. Leased Internet connections are limited to large corporations and universities who could afford the cost. Fig. 33.
6 IN-TEXT QUESTION 33. 2 1. State whether the following statements are True or False. (a) WWW is the acronym for the World Wide Web.
(b) In TCP/IP connection, the user will get only textual matter of a Web Page. (c) Gateway Access is also known as Level-One connection. (d) Good example of network with Level One connectivity within India is that of VSNL (e) E-mail is known as URL (Uniform Resource Locator).
(f) Leased connection is also known as direct Internet access or Level Three connection.
33. 6 WHAT YOU HAVE LEARNT In this lesson you learnt the history of Internet. Also you learnt the various types of services provided by Internet. In the process you could understand the concept of e-mail and file transfer protocol. By now you should be in a position to access Internet and put it to various uses.
33. 7 TERMINAL QUESTIONS 1. Explain in brief the concept of e-mail. 2. What are the basic objectives of FTP? 3.
What is the difference between Leased connection and Dialup connection? 4. Explain in brief (a) TCP/IP connection (b) Telnet (c) Gateway Access (d) Shell connection 33. 8 FEEDBACK TO IN-TEXT QUESTIONS IN-TEXT QUESTION 33. 1 1. (a) protocol (b) internet utility (c) mailserver (d) local internet service provider (e) data IN-TEXT QUESTION 33. 2 1.
(a) True (b) False (c) True (d) True (e) False (f) True 34 PUBLISHING ON THE WEB: AN INTRODUCTION 34. 1 INTRODUCTION In the previous lesson we had discussed about the concept of World Wide Web (WWW).
Web page design is exciting and can provide an interesting challenge for any body. In this lesson we will introduce you to the concept of web page designing. You will come to know that with its rapid growth, Internet or web has given access to more and more users.
However each and every user accesses or uses the web in a different way than the other. As per statistics, more women and children are using the web and in different ways than the male users. The development of web page is for a specific audience. Hence, it is essential for a web designer to know who the audience are. For example if you teach high school mathematics, your primary audience is your class and secondary audience are other students, colleagues, parents, and your local community. With Internet and web pages both the organisation and the individual involved will gain mileage.
For an organisation, this would provide i) a low cost information distribution system, ii) make database available for others to use, and maintain the security, iii) collect information provided by others on Internet to expand and improve service to a target audience, and iv) provide low-cost training. On the other hand for an individual it would mean i) get acquainted with new technology, ii) learn new skills, iii) receive low cost training and other information, and iv) get connected with other web creators with ease. 34. 2 OBJECTIVES After going through this lesson you should be in a position to? explain the concepts of the Internet and web publishing? access Internet? design web pages? work with HTML 34.
3 WEB PUBLISHING When you browse the Internet you will come across quite often the word home page. Home page is the entry or starting point of a website. It is more or less in the format of the contents of a book or magazine. In other words it is the welcome page of the website you are visiting, which in most cases gives an overview of what the website contains.
One should not be surprised to see only one page in a website. Website can have one or more than one page, or a few long ones, depending on it’s design. But normally the website contains more than one page. Web pages vary in their look and content, but most of them follow a traditional book or magazine format. At the top of the page resides the master head or heading or banner graphic giving the main theme of the page. Then there is a list of items, such as subjects, with a brief description.
The items listed are either hot or cold. When we say they are hot, it means they are linked to other pages within the same website or to other websites. These links are highlighted words in the body of the text, or in a list, or they can even be the images that link to other content. But how you will know the text is hot or cold. Usually the hot text appears in different colour from the rest of the text – usually in blue and underlined. When one moves the cursor over this text or graphics link, it will change from an arrow to a hand shape.
And when you click on the hot text or image, you will be taken to the linked web page or website. Once you come back to a page with a link you have already visited, the hot text or hypertext words will appear in a different colour other than blue, so you know you have already visited there. But that does not prevent you from visiting the link again and again, you can certainly go there as many times, as you like. As the information and links are not static, don’t feel surprised if the page looks different and the information has changed, when you visit a site, next time.
The Internet is a dynamic medium of communication for displaying information. To encourage visitors to return to a site, it is very much required to change the look and feel of the web pages from time to time. (a) Planning Cycle Web planning involves a structured approach involving conceptualization of design and organizing the web developer and information resources required making the designing a reality. If the design is for a large and complex site, it is always advisable to note down all the planning, preferably in a notebook. This note book can be used as a guide to deliver all the raw material needed for web designing such as: HTML, Java scripts, graphics, text, animation and icons, etc. You should also get ready with the policies and guidelines to be followed for developmental activities to give the web sites a professional touch.
This requires careful planning. Create the sketch of the site, before the actual development work takes place. This will help to reduce the re-work while development is on. Basically this will act as a site roadmap to be followed by the web designer to create the actual web sites. The most critical part a web page is its content.
While working on content for a web page, it is necessary to take the target audience into consideration. Collect all the materials such as brochure, contact information, review, lessons, teaching material, quiz, FAQ’s, photographs etc. It is not necessary to use all of them in one go, but they will be handy when something needs to be changed. Once the conceptualization, collection of materials and creation of roadmap of the site is ready, it is time to decide how you are going to publish your site or how the web users will come to know about your site. Take the help of promotional Internet sites, professional organizations etc.
(b) Design Cycle Now let us look how user designs the web page from an information design perspective pointed view and not from a graphics design. Web page contents should not have more graphic page. In fact, the basic idea about a web page is information sharing enhanced by other elements such as graphics, animation, etc. (c) Design Basics Following are some basic steps to be followed while creating web pages. ? Create a Welcom/Index / first page of your web site. ? Avoid use of heavy graphics in the first page from the user’s point of view.
? Page should be descriptive and interactive both as per requirements. Some minimum technical requirements might include: ? Fast loading of pages? Presentation with clarity and readability – with or without graphics? Validation of the contents? Easy and clear navigation? Instruction on how to use the site. Identify and address all potential problems such as: ? Slow connections? Physical constraints of the user such as sight or hearing impaired visitors? Platform support? Browser support etc. 34.
4 HTML (HYPERTEXT MARKUP LANGUAGE) So far we have discussed the points you should be careful about while designing a web page. But what language we should use for creating web pages? HTML or Hyper Text Markup Language is used for creating web pages. Although HTML stands for HyperText Markup Language, it is not a programming language like Java. The basic function of the HTML is to describe the standard (-) how a browser should display text and multimedia elements such as graphics, animation, etc. It works on a limited number of tags and is not difficult to learn and use.
Let us learn how it works. How HTML works? The HTML is platform independent that is computer and computer operating system on which it is running. It means that HTML uses a small number of tags to create Web page. Any Web server regardless of their location and operating system can publish these web pages. These web pages can also be viewed or displayed by any Web browser regardless of the platform on which it is running. ? As we have discussed, HTML works on tags.
These HTML tags control the page structure and the style sheet controls the details about page layout and their presentation. In other words, HTML style sheet provides consistency and creativity to create professional quality web pages. ? The basic structure of using tag is some text. For example, the tag for making text bold is this is bold. And when displayed in a browser it will be displayed, as this is bold. ? Web page is made up of two sections: head and body.
Each of these sections is enclosed within a pair of tags. The head section describes the page content while the body section defines the web page look and feel. Most of HTML tags are used in the body section, whereas the number of tags is limited in the head section. The standard web page structure in HTML is Title of the page is given here web page contents goes here IN-TEXT QUESTION 34. 1 1.
State whether the following statements are True or False (a) Hyper Text Makeup Language is used for creating web pages. (b) The HTML is platform independent. (c) Hyper Text Markup Language is a programming language like Java. (d) All web page starts with a welcome page.
(e) Web page is made up of two sections head and body. (f) Use of heavy graphics will lead to slow loading of pages. (g) Web pages can not be descriptive and interactive. 34. 5 GETTING STARTED WITH HTML Before you actually start using HTML, you need certain things such as: (a) Text Editor To create an HTML document, a text editor is required. Any text editor, which can save the file in plain ASCII format, is good enough for creating HTML file.
You can use right from MS-DOS editor “EDIT” to Microsoft Word for creating HTML document. (b) Web Browser After creating an HTML document, it is required to be viewed in a browser to see how it looks. There are several browsers available for viewing HTML documents such as Netscape Navigator, NCSA Mosaic, Microsoft Internet Explorer, Web Explorer etc. But most popular among them are Microsoft Internet Explorer and Netscape Navigator. However, it is advisable to use at least two browsers to experiment with the look and feel of the developed web pages. (c) Graphics Tool Internet supports only GIF (Graphics File Format).
Any other graphics file such as BMP, PCX, etc needs to be converted in GIF format to be used in Internet. So you must use graphics software that are capable of creating GIF graphics file. There are a number of graphics packages available such as Adobe PhotoShop, Adobe Illustrator, etc, which support GIF file. (d) Content The actual contents of a web page are – all of the words, images, and links, which a web user can read and interact with. So all your content should be well documented and well researched before they are put in the web page. All graphics, Icons, etc.
should be of correct impact. (e) Hyperlink Hyperlink is used to link between pages. A well-designed web page should have proper and meaningful links to other documents or web pages. The hyperlink can be a highlighted text in the document or images in the document.
34. 6 USING HTML TAGS The HTML document uses HTML tags, be it in the beginning of the document or end of it. These tags tell a Web browser where the HTML in the document begins and ends. The HTML document starts with a tag called and ends with a tag. i. e.
The first tag indicates the beginning of the HTML document and the last tag indicates the end of the document. Within these two resides the body of the HTML which defines the look and feel of the web page. All the HTML tags end with the same tag name, but with a prefix of ‘/’ with the tag name such as. (a) Head The second tag in the HTML document is. This tag contains all header information about the document such as document title, author name, etc. It ends with.
(b) Title This appears within the Head tag structure. This is where the title of the web page should be given, which will appear at the top of the browser’s title bar, and also in the history list. The title of the document should be logically related to the content of the web page, and must be short but informative enough about the web page. As a norm, there should only be one title per document.
(c) Body The actual works lies in the Body of the document. This appears after the Head tags. Between the Body tags, remains all the stuff that gets displayed in the browser window like all of the text, graphics, and links. (d) Headings As we know, the entire HTML document contains information that appears in different parts or section titles. There are a total of six levels of headings, from Heading 1 through Heading 6. They are marked as H 1 for heading one and H 6 for heading six.
Heading 1 (H 1) is “most important” and Heading 6 (H 6) is “least important” in an HTML document. Given below are the structure of all six heading tags: Heading 1 Heading 2 Heading 3 Heading 4 Heading 5 Heading 6 A heading in an HTML document always begins at the margin of a line. It also forces a line break at the end of the heading. In other words, there cannot be two headings on the same line. (e) Paragraphs Paragraphs are treated as the most basic structures in HTML.
Presetting information in paragraphs is quite common in Web pages. Paragraph tags are for beginning of the paragraph and for the end. In other words in HTML creation, the beginning of a paragraph is marked by, and the end by. (f) Lists As the name suggests, lists is the index of items to be appeared in a web page in a specific format. There are three types of lists, namely Unordered, Ordered and Definition lists. Out of these three most widely used lists are un-ordered and Ordered list.
Let us discuss them one by one. (i) Unordered lists While reading Microsoft Word you have known the ‘Bullet List’. It is a list of items, where each listed item is preceded by a ‘bullet’ (a small black circle).
In HTML, this bulleted list is termed as ‘Unordered list’. Unordered list starts with a tag and ends with a tags.
Now all the items to be listed start with an HTML tag, which stands for “List Item.” has a corresponding closing tag, but this closing tag is not compulsory to be given. There is no limitation to the number of list of items. Here is an example of Unordered List of items; Windows 95 MS-DOS Graphics Animation Internet And the result will be: ? Windows 95? MS-DOS? Graphics? Animation? Internet Almost anything can be put into a list item – line breaks, entire paragraphs, images, links, or even other lists. (ii) Ordered lists In HTML, both unordered and ordered list looks similar and same set of rules applies to both of them. However, the differences between both of them is that instead of using and, an ordered list is contained within the tags and and the list items are preceded by numbers such as 1, 2, 3 and so on instead of a ‘Bullet’.
However, when an ordered list is displayed in a Web browser, it uses an automatically generated sequence of items. Here is an example of Ordered List of items; Windows 95 MS-DOS Graphics Animation Internet And the result will be: 1. Windows 95 2. MS-DOS 3. Graphics 4. Animation 5.
Internet As in the case of unordered list, almost anything can be put into a list item – line break, entire paragraphs, images, links, or even other lists. They can also be nested as unordered lists. Unordered lists can be nested in ordered lists, vice versa. For example; Rakesh Harish Manoj Swati Reena 21 yrs.
20 yrs. 25 yrs. 19 yrs. 20 yrs.
This will result in? Rakesh? Harish? Manoj? Swati? Reena 1. 21 yrs. 2. 20 yrs. 3. 25 yrs.
4. 19 yrs. 5. 20 yrs. 34. 7 CHARACTER STYLE TAGS In addition to the above there can also be character style tags used for bold, italics, underline etc.
They are sometimes called forced style tags, because their very nature forces a certain style on the character. The three most commonly used character style tags are: (a) Boldface This tag is used to make characters boldface. The tags used are and. And everything between and is boldfaced. For example, This is a Web Page will result in This is a Web Page. (b) Italics HTML tags and are used to put the characters in Italics.
Everything between and is italicized. For example, This is a Web Page will result in This is a Web Page. (c) Underline As the name suggests, the Underline tags and are used to put character in underlined format. That means everything between and should be underlined.
For example, This is a Web Page will result in This is a Web Page. 34. 8 THE HTML ANCHOR OR LINKS As we have already discussed, a well-designed web page will have links to other pages and even to the outside world. These links can be a word within the text or an image in the document and they can appear anywhere in the HTML document. The links in HTML document starts with a tag and ends with. However, the tags are not used alone, but this will contain attribute like HREF…
HREF HREF stands for “Hypertext REFerence”, which indicates the location of the file to be linked to current page. The links are in the form of, where URL is the location of the resource to which the file to be linked. For example, the National Open School Web server is at ” web .” A sentence, which contained a link to that address, would look something like below: For further information, please check out the National Open School Web server. The words between and the open and close of the anchor (“National open School Web server”) will be displayed as a hyperlink. Here is how it will look like National Open School Web server! Clicking that link from a Web browser will load the National Open School Web server’s main or index page. (a) IMG Till now we have discussed how to create and format text in an HTML document.
Image also plays an important role in Web page creation. Images are inserted in Web documents using the IMG tag and this tag has no closing tag such as. However an tag requires the location of the images file that is supposed to be placed in the document. This does not essentially mean that the said image file will be included in the HTML file. Visually, images are part of a Web page, but in reality an HTML file and any graphics it refers to are all separate files.
All the referred graphics files are stored as individual files in the web server and they don’t have to be in the same directory as the HTML document. But it is a good practice to put all the graphics files in a separate folder or directory preferably by images directory for easy location and manipulation. But tags alone does not help to place images in the HTML document. For tags to work, you need another attribute called ‘SRC’. This attribute, which stands for ‘source’ or ‘source of this graphics’ points to location of the graphics file.
The source can either be a URL giving path for outside server or a path in the same server where the graphics file is stored. When this attribute is used along with tags, a typical image tag will look like; In other words, if there is a graphics file called ‘welcome. gif’ in NOS web server’s graphics folder than the above image tags will look like The browser will put the graphic ‘welcome. gif’ wherever an image tag occurs in the document. Browser will treat this as another piece of text. Images can be placed almost anywhere within the body of the document, they can be between words, paragraphs, within paragraphs, in list items or even a link.
IN-TEXT QUESTION 34. 2 1. Fill in the blanks (a) To create HTML document, a is required. (b) HTML tags and are used to put the characters in. (c) Internet supports only graphics files format. (d) starts with a tag and ends with a tag.
(e) is used to link between pages. 34. 9 WHAT YOU HAVE LEARNT In this lesson you learnt the concept of web page designing. You learnt that you can create a web page through html. Before creating a web page you should be clear about its purpose and client groups. Hence, planning cycle, design cycle and design basics are important.
34. 10 TERMINAL QUESTIONS 1. What are the basic steps to be followed while creating web pages. Explain in brief. 2.
What are the steps you need while starting HTML? . 3. Explain the following (a) Character style tags (b) Ordered lists (c) Paragraphs (d) Headings 34. 11 FEEDBACK TO IN-TEXT QUESTIONS IN-TEXT QUESTION 34. 1 1. (a) False (b) True (c) False (d) True (e) True (f) True (g) False IN-TEXT QUESTION 34.
2 1. (a) Text editor (b) Italics (c) GIF (d) Unordered list (e) Hyperlink 35 THE CONCEPT OF MULTIMEDIA 35. 1 INTRODUCTION As the name suggests, multimedia is a set of more than one media element used to produce a concrete and more structured way of communication. In other words multimedia is simultaneous use of data from different sources. These sources in multimedia are known as media elements.
With growing and very fast changing information technology, Multimedia has become a crucial part of computer world. Its importance has realised in almost all walks of life, may it be education, cinema, advertising, fashion and what not. Throughout the 1960 s, 1970 s and 1980 s, computers have been restricted to dealing with two main types of data – words and numbers. But the cutting edge of information technology introduced faster system capable of handling graphics, audio, animation and video. And the entire world was taken aback by the power of multimedia. 35.
2 OBJECTIVES After going through this lesson you should be able to? explain what is multimedia? understand the importance of individual media elements? identify different hardware components required to run a multimedia? appreciate the impact of audio in educational presentation? describe how visual images, graphics and audio can be added to a presentation? enhance the capability of multimedia through interactive video impact 35. 3 WHAT IS MULTIMEDIA? Multimedia is nothing but the processing and presentation of information in a more structured and understandable manner using more than one media such as text, graphics, animation, audio and video. Thus multimedia products can be an academic presentation, game or corporate presentation, information kiosk, fashion-designing etc. Multimedia systems are those computer platforms and software tools that support the interactive uses of text, graphics, animation, audio, or motion video. In other words, a computer capable of handling text, graphics, audio, animation and video is called multimedia computer. If the sequence and timing of these media elements can be controlled by the user, then one can name it as Interactive Multimedia.
35. 4 DIFFERENT MEDIA ELEMENTS (i) Text Inclusion of textual information in multimedia is the basic step towards development of multimedia software. Text can be of any type, may be a word, a single line, or a paragraph. The textual data for multimedia can be developed using any text editor. However to give special effects, one needs graphics software which supports this kind of job. Even one can use any of the most popular word processing software to create textual data for inclusion in multimedia.
The text can have different type, size, color and style to suit the professional requirement of the multimedia software. (ii) Graphics Another interesting element in multimedia is graphics. As a matter of fact, taking into consideration the human nature, a subject is more explained with some sort of pictorial / graphical representation, rather than as a large chunk of text. This also helps to develop a clean multimedia screen, whereas use of large amount of text in a screen make it dull in presentation. Unlike text, which uses a universal ASCII format, graphics does not have a single agreed format.
They have different format to suit different requirement. Most commonly used format for graphics is. BMP or bitmap pictures. The size of a graphics depends on the resolution it is using.
A computer image uses pixel or dots on the screen to form itself. And these dots or pixel, when combined with number of colors and other aspects are called resolution. Resolution of an image or graphics is basically the pixel density and number of colors it uses. And the size of the image depends on its resolution. A standard VGA (Virtual Graphics Arrays) screen can display a screen resolution of 640? 480 = 307200 pixel. And a Super VGA screen can display up-to 1024? 768 = 786432 pixel on the screen.
While developing multimedia graphics one should always keep in mind the image resolution and number of colors to be used, as this has a direct relation with the image size. If the image size is bigger, it takes more time to load and also requires higher memory for processing and larger disk-space for storage. However, different graphics formats are available which take less space and are faster to load into the memory. There are several graphics packages available to develop excellent images and also to compress them so that they take lesser disk-space but use higher resolution and more colours. Packages like Adobe PhotoShop, Adobe Illustrator, PaintShop Pro etc. are excellent graphics packages.
There are Graphics gallery available in CD’s (Compact Disk) with readymade images to suit almost every requirement. These images can directly be incorporated into multimedia development. (iii) Animation Moving images have an overpowering effect on the human peripheral vision. Followings are few points for its popularity. Showing continuity in transitions: Animation is a set of static state, related to each other with transition. When something has two or more states, then changes between states will be much easier for users to understand if the transitions are animated instead of being instantaneous.
An animated transition allows the user to track the mapping between different subparts through the perceptual system instead of having to involve the cognitive system to deduce the mappings. Indicating dimensionality in transitions: Sometimes opposite animated transitions can be used to indicate movement back and forth along some navigational dimension. One example used in several user interfaces is the use of zooming to indicate that a new object is “grown” from a previous one (e. g. , a detailed view or property list opened by clicking on an icon) or that an object is closed or minimized to a smaller representation.
Zooming out from the small object to the enlargement is a navigational dimension and zooming in again as the enlargement is closed down is the opposite direction along that dimension. Illustrating change over time Since animation is a time-varying display, it provides a one-to-one mapping to phenomena that change over time. For example, deforestation of the rain forest can be illustrated by showing a map with an animation of the covered area changing over time. Multiplexing the display Animation can be used to show multiple information objects in the same space.
A typical example is client-side image maps with explanations that pop up as the user moves the cursor over the various hypertext anchors. Enriching graphical representations Some types of information are easier to visualize with movement than with still pictures. Consider, for example, how to visualize the tool used to remove pixels in a graphics application. Visualizing three-dimensional structures As you know the computer screen is two-dimensional. Hence users can never get a full understanding of a three-dimensional structure by a single illustration, no matter how well designed. Animation can be used to emphasize the three-dimensional nature of objects and make it easier for users to visualize their spatial structure.
The animation need not necessarily spin the object in a full circle – just slowly turning it back and forth a little will often be sufficient. The movement should be slow to allow the user to focus on the structure of the object. You can also move three-dimensional objects, but often it is better if you determine in advance how best to animate a movement that provides optimal understanding of the object. This pre-determined animation can then be activated by simply placing the cursor over the object.
On the other hand, user-controlled movements requires the user to understand how to manipulate the object (which is inherently difficult with a two-dimensional control device like the mouse used with most computers – to be honest, 3 D is never going to make it big time in user interfaces until we get a true 3 D control device).
Attracting attention Finally, there are a few cases where the ability of animation to dominate the user’s visual awareness can be turned to an advantage in the interface. If the goal is to draw the user’s attention to a single element out of several or to alert the user to updated information then an animated headline will do the trick. Animated text should be drawn by a one-time animation (e.
g. , text sliding in from the right, growing from the first character, or smoothly becoming larger) and never by a continuous animation since moving text is more difficult to read than static text. The user should be drawn to the new text by the initial animation and then left in peace to read the text without further distraction. One of the excellent software available to create animation is Animator Pro. This provides tools to create impressive animation for multimedia development. Video Beside animation there is one more media element, which is known as video.
With latest technology it is possible to include video impact on clips of any type into any multimedia creation, be it corporate presentation, fashion design, entertainment games, etc. The video clips may contain some dialogues or sound effects and moving pictures. These video clips can be combined with the audio, text and graphics for multimedia presentation. Incorporation of video in a multimedia package is more important and complicated than other media elements. One can procure video clips from various sources such as existing video films or even can go for an outdoor video shooting.
All the video available are in analog format. To make it usable by computer, the video clips are needed to be converted into computer understandable format, i. e. , digital format. Both combinations of software and hardware make it possible to convert the analog video clips into digital format. This alone does not help, as the digitised video clips take lots of hard disk space to store, depending on the frame rate used for digitisation.
The computer reads a particular video clip as a series of still pictures called frames. Thus video clip is made of a series of separate frames where each frame is slightly different from the previous one. The computer reads each frame as a bitmap image. Generally there are 15 to 25 frames per second so that the movement is smooth. If we take less frames than this, the movement of the images will not be smooth. To cut down the space there are several modern technologies in windows environment.
Essentially these technologies compress the video image so that lesser space is required. However, latest video compression software makes it possible to compress the digitised video clips to its maximum. In the process, it takes lesser storage space. One more advantage of using digital video is, the quality of video will not deteriorate from copy to copy as the digital video signal is made up of digital code and not electrical signal. Caution should be taken while digitizing the video from analog source to avoid frame droppings and distortion. A good quality video source should be used for digitization.
Currently, video is good for: l promoting television shows, films, or other non-computer media that traditionally have used trailers in their advertising. l giving users an impression of a speaker’s personality. l showing things that move. For example a clip from a motion picture. Product demos of physical products are also well suited for video. Audio Audio has a greater role to play in multimedia development.
It gives life to the static state of multimedia. Incorporation of audio is one of the most important features of multimedia, which enhance the multimedia usability to its full potential. There are several types of sound, which can be used in multimedia. They are human voices, instrumental notes, natural sound and many more. All these can be used in any combination as long as they give some meaning to their inclusion in multimedia.
There are many ways in which these sounds can be incorporated into the computer. For example; l Using microphone, human voice can directly be recorded in a computer. l Pre-recorded cassettes can be used to record the sound into computer. l Instrumental sound can also be played directly from a musical instrument for recording into the computer. The sound transmitted from these sources is of analog nature. To enable the computer to process this sound, they need to be digitised.
As all of us know that sound is a repeated pattern of pressure in the air and a microphone converts a sound wave into an electrical wave. The clarity of sound, the final output depends entirely on the shape and frequency of the sound wave. When digitised (recording into computer), the error in sound can be drastically reduced. Audio need to be converted into digital format to produce digitised audio in order to use them in multimedia. And these digitised sounds again can be re-converted into analog form so that the user can hear them though the speakers.
Musical Instrument Digitisation Interface or MIDI provides a protocol or a set of rules, using which the details of a musical note from an instrument is communicated to the computer. But MIDI data is not digitized sound. It is directly recorded into the computer from musical instruments, whereas digitised audio is created from the analog sound. The quality of MIDI data depends upon the quality of musical instrument and the sound system. A MIDI file is basically a list command to produce the sound. For example, pressing of a guitar key can be represented as a computer command.
When the MIDI device processes this command, the result will be the sound from the guitar. MIDI files occupy lesser space as compared to the digitised audio and they are editable also. The main benefit of audio is that it provides an exclusive channel that is separate from that of the display. Speech can be used to offer commentary or help without obscuring information on the screen. Audio can also be used to provide a sense of place or mood. Mood-setting audio should employ very quiet background sounds in order not to compete with the main information for the user’s attention.
Music is probably the most obvious use of sound. Whenever you need to inform the user about a certain work of music, it makes much more sense to simply play it than to show the notes or to try to describe it in words. IN-TEXT QUESTION 35. 1 1. State whether the following statements are True or False.
(a) A computer capable of handling text, graphics, audio, animation and video is called multimedia computer. (b) MIDI data is digitized sound. (c) Animation can be used to emphasize the three-dimensional nature of objects. (d) Most commonly used format for graphics is. BMP or bitmap pictures. (e) If the sequence and timing of these multimedia elements can be controlled by the user, then one can name it as Non-Interactive Multimedia.
35. 4 MULTIMEDIA HARDWARE REQUIREMENTS For producing multimedia you need hardware, software and creativity. In this section we will discuss the multimedia equipment required in a personal computer (PC) so that multimedia can be produced. (a) Central Processing Unit As you know, Central Processing Unit (CPU) is an essential part in any computer. It is considered as the brain of computer, where processing and synchronization of all activities takes place.
The efficiency of a computer is judged by the speed of the CPU in processing of data. For a multimedia computer a Pentium processor is preferred because of higher efficiency. However, the CPU of multimedia computer should be at least 486 with math coprocessor. The Pentium processor is one step up the evolutionary chain from the 486 series processor and Pentium Pro is one step above the Pentium. And the speed of the processor is measured in megahertz. It defines the number of commands the computer can perform in a second.
The faster the speed, the faster the CPU and the faster the computer will be able to perform. As the multimedia involves more than one medial element, including high-resolution graphics, high quality motion video, and one need a faster processor for better performance. In today’s scenario, a Pentium processor with MMX technology and a speed of 166 to 200 MHz (Megahertz) is an ideal processor for multimedia. In addition to the processor one will need a minimum 16 MB RAM to run WINDOWS to edit large images or video clips. But a 32 or 64 MB RAM enhances the capacity of multimedia computer.
(b) Monitor As you know that monitor is used to see the computer output. Generally, it displays 25 rows and 80 columns of text. The text or graphics in a monitor is created as a result of an arrangement of tiny dots, called pixels. Resolution is the amount of details the monitor can render. Resolution is defined in terms of horizontal and vertical pixel (picture elements) displayed on the screen. The greater the number of pixels, better visualization of the image.
Like any other computer device, monitor requires a source of input. The signals that monitor gets from the processor are routed through a graphics card. But there are computers available where this card is in-built into the motherboard. This card is also called the graphics adapter or display adapter. This card controls the individual pixels or tiny points on a screen that make up image. There are several types of display adapter available.
But the most popular one is Super Virtual Graphics Arrays (SVGA) card and it suits the multimedia requirement. The advantage of having a SVGA card is that the quality of graphics and pictures is better. Now the PCs, which are coming to the market, are fitted with SVGA graphics card. That allows images of up to 1024? 768 pixels to be displayed in up to 16 millions of colours. What determines the maximum resolution and color depth is the amount of memory on the display adapters. Often you can select the amount of memory required such as 512 KB, 1 MB, 2 MB, 4 MB, etc.
However, standard multimedia requirement is a 2 MB of display memory (or Video RAM).
But one must keep in mind that this increases the speed of the computer, also it allows displaying more colours and more resolutions. One can easily calculate the minimum amount of memory required for display adapter as (Max. Horizontal Resolution x Max.
Vertical Resolution? Colour Depths. in Bits) /8192 = The minimum video (or display) memory required in KB. For example, if SVGA resolution (800? 600) with 65, 536 colours (with colour depth of 16) you will need = 937. 5 KB, i. e.
, approximately 1 MB of display memory. Another consideration should be the refresh rate, i. e. , the number of times the images is painted on the screen per second.
More the refresh rate, better the image formation. Often a minimum of 70-72 Mhz is used to reduce eye fatigue. As a matter of fact higher resolution requires higher refresh rates to prevent screen flickers. (c) Video Grabbing Card As we have already discussed, we need to convert the analog video signal to digital signal for processing in a computer. Normal computer will not be able to do it alone. It requires special equipment called video grabbing card and software to this conversion process.
This card translates the analog signal it receives from conventional sources such as a VCR or a video camera, and converts them into digital format. The software available with it will capture this digital signal and store them into computer file. It also helps to compress the digitized video so that it takes lesser disk space as compared to a non-compressed digitized video. This card is fitted into a free slot on the motherboard inside the computer and gets connected to an outside source such as TV, VCR or a video camera with the help of a cable. This card receives both video and audio signal from the outside source and conversion from analog to digital signal takes place. This process of conversion is known as sampling.
This process converts the analog signal to digital data streams so that this signal can be stored in binary data format of 0’s and 1’s. This digital data stream is then compressed using the video capturing software and stores them in the hard disk as a file. This file is then used for incorporation into multimedia. This digitized file can also be edited according to the requirements using various editing software such as Adobe Premiere. A number of digitizer or video grabbing cards are available in the market. However, one from Intel called Intel Smart Video Recorder III does a very good job of capturing and compressing video.
(d) Sound Card Today’s computers are capable of creating the professional multimedia needs. Not only you can use computer to compose your own music, but it can also be used for recognition of speech and synthesis. It can even read back the entire document for you. But before all this happens, we need to convert the conventional sound signal to computer understandable digital signals. This is done using a special component added to the system called sound card. This is installed into a free slot on the computer motherboard.
As in the case of video grabber card, sound card will take the sound input from outside source (such as human voice, pre-recorded sounds, natural sounds etc. ) and convert them into digital sound signal of 0’s and 1’s. The recording software used alongwith the sound card will store this digitised sound stream in a file. This file can latter be used with multimedia software. One can even edit the digitised sound file and add special sound effects into it. Most popular sound card is from Creative Systems such as Sound Blaster-16, AWE 32, etc.
AWE 32 sound card supports 16 channel, 32 voice and 128 instruments and 10 drums sound reproduction. It also has CD-ROM interface. (e) CD-ROM Drive CD-ROM is a magnetic disk of 4. 7 inches diameter and it can contain data up to 680 Megabytes. It has become a standard by itself basically for its massive storage capacity, faster data transfer rate.
To access CD-ROM a very special drive is required and it is known as CD-ROM drive. Let us look into the term ROM that stands for ‘Read Only Memory’. It means the material contained in it can be read (as many times, as you like) but the content cannot be changed. As multimedia involves high resolution of graphics, high quality video and sound, it requires large amount of storage space and at the same time require a media, which can support faster data transfer. CD-ROM solves this problem by satisfying both requirements. Similar to the hard disk drive, the CD-ROM drive has certain specification which will help to decide which drive suit best to your multimedia requirement.
(i) Transfer Rate Transfer rate is basically the amount of data the drive is capable of transferring at a sustained rate from the CD to the CPU. This is measured in KB per second. For example, 1 x drive is capable of transferring 150 KB of data from the CD to the CPU. In other terms 1 x CD drive will sustain a transfer rate of 150 KB/sec, where x stands for 150 KB. This is the base measurement and all higher rates are multiple of this number, x. Latest CD-ROM drive available is of 64 x, that means it is capable of sustaining a data transfer rate of 64 x 150 = 9600 KB = 9.
38 MB per second from the CD to the CPU. (ii) Average Seek time The amount of time lapses between request and its delivery is known as average seeks time. The lower the value better the result and time is measured in milliseconds. A good access time is 150 ms. Recently computer technology has made tremendous progress. You can now have CDs which can ‘write many, read many’ times.
This means you can write your files in to a blank CD through a laser beam. The written material can be read many times and they can even be erased and re-written again. Basically this re-writable CD’s can be used a simple floppy disk. (f) Scanner Multimedia requires high quality of images, graphics to be used. And it takes lot of time creating them. However there are ready-made sources such as real life photographs, books, arts, etc.
available from where one easily digitized the required pictures. To convert these photographs to digital format, one need a small piece of equip me.