In 1989, Tim Berners-Lee introduced to the world the World Wide Web (WWW) which is now distributed all over the world through the Internet. This system is today developed into a medium to communicate multimedia based information. The WWW has some agreed standards on the following.
1. How to organize the multimedia and other information.
2. How to store such organized information in the computer system.
3. How to link information in one computer to information in another computer
in the network.
4. How to retrieve such information.
5. How to use information.
A computer named ‘WWW Server’ in the network is used to store web pages organized using the above standards and the other computers in the network can obtain information in these web pages. One ‘WWW Server’ can be used to store websites of various organizations or individuals and every website has a ‘Home page’ and other web pages of the site are linked to the home page using ‘Hyperlinks’ or ‘Hyper-media’. The main feature of the ‘WWW Server’ system with web pages which are connected through ‘Hyperlink’ or ‘Hyper-media’ is that the information can be obtain in any order, any time by anybody (there are systems in which information
should be given in a particular order. The information provided through radio and televisions are examples of such information). Using ‘Hyper-media’ links an important item in a web page can be linked to a another web page in the same computer system or to a web page in another ‘WWW-Server’ in the Internet to get more detailed information about the item. It is possible to state four possible situations where such links can be established.
2. A link to a web page in the same web site.
3. A link to another web site in the Internet.
4. A link to another web page in another website in the Internet.
Another important feature of the ‘WWW’ is the ability to link different multimedia information. For example a link can be established to an image, video clip, sound clip or an animation picture.
If the files in the Internet are developed using only text, it is easy to obtain such files from the Internet. In order to prepare web based files, a special language called HTML (Hypertext Markup Language) can be used which has some special tags to indicate the type of information in the file using a specified set of rules. The HTML has some special instruction codes (tags) to incorporate image, sound, video and animation into a web file. A software tool call ‘Web Browser’ is needed to access the information in a web file. The Web browser interprets the instruction codes in a HTML file and provides the information in a web file in an appropriate way to the user on the monitor of the computer. The process takes place in four steps.
1. First a request is made to the computer which provides the information and
checks whether information can be obtained .
2. If information can be obtained in this way the information will be provided to
the client computer which requests information using ‘HTTP’ technology.
3. The information provided will be displayed on the client computer in an
appropriate way according to the HTML tags in the file by the web browser.
4. If any image or multimedia content is to be displayed or played this will be
executed using the tools in the client computer.
In addition to the standard tags in ‘HTML’, other software tools (‘Plug-ins’) with various capabilities developed by different companies can be incorporated in to an HTML file. This will give value addition to the retrieval of content in the Internet. HTML is a kind of word processor and a HTML file can be used in a computer with any operating system. The facilities of a word processor such as creation of fonts of varies sizes and shapes, title and sub title creation, tables, lists, paragraphs and different features in paragraphs can be done using HTML. In addition to this the multimedia files like images, sounds, animations and videos can be incorporated into an HTML file.
A web browser is needed to obtain the large information in the WWW which can be used in any computer. Some of these web browsers can be downloaded from the Internet without paying any fee. Some of the widely used web browsers are ‘Firefox’, ‘Internet Explorer’, ‘Safari’, ‘Opera’ and ‘Google Chrome’. These web browsers retrieve and provide information in a very user friendly way by point and click of a mouse. The basic capabilities of a web browser are given below.
¨ The ability to display an HTML file in plain text according to the
HTML tags in the file.
¨ The ability to display web pages with images having an image file
format GIF, JPG or PNG.
¨ The ability to play other multimedia files in an HTML file such as
sound, video and animation.
¨ The ability to access web sites with ‘FTP’, Gopher’ and ‘Usenet’
facilities.
¨ The ability to provide facility to input user information in a form and
obtain such information.
¨ The ability to provide access to search engines so that the user can
search information on web pages or web sites which he or she needs.
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