World Wide Web in Computer Network

Introduction to World Wide Web

• The World Wide Web (WWW) is a collection of documents and other web resources which are identified by URLs, interlinked by hypertext links, and can be accessed and searched by browsers via the Internet.
• World Wide Web is also called the Web and it was invented by Tim Berners-Lee in 1989.
• Website is a collection of web pages belonging to a particular organization.
• The pages can be retrieved and viewed by using browser.

• The client wants to see some information that belongs to site 1.
• It sends a request through its browser to the server at site 2.
• The server at site 1 finds the document and sends it to the client.

Client (Browser):

• Web browser is a program, which is used to communicate with web server on the Internet.
• Each browser consists of three parts: a controller, client protocol and interpreter.
• The controller receives input from input device and use the programs to access the documents.
• After accessing the document, the controller uses one of the interpreters to display the document on the screen.

Server:

• A computer which is available for the network resources and provides service to the other computer on request is known as server.
• The web pages are stored at the server.
• Server accepts a TCP connection from a client browser.
• It gets the name of the file required.
• Server gets the stored file. Returns the file to the client and releases the top connection.

Uniform Resource Locater (URL)

• The URL is a standard for specifying any kind of information on the Internet.
• The URL consists of four parts: protocol, host computer, port and path.
• The protocol is the client or server program which is used to retrieve the document or file. The protocol can be ftp or http.
• The host is the name of computer on which the information is located.
• The URL can optionally contain the port number  and it is separated from the host name by a colon.
• Path is the pathname of the file where the file is stored.