HTTP is a connectionless text depend protocol. Clients (web browsers) send requests to web servers for web elements like web pages and images. After the request is serviced through a server, the connection among client & server across the Internet is disconnected. A new connection should be made for each request. Most of the protocols are connection oriented. It means that the two computers communicating to each other keep the connection open over the Internet. However, HTTP does not. Before an HTTP request can be made through a client, a new connection has to be made to the server.
While you type a URL into a web browser, this is what happens:
1. If the URL has a domain name, first the browser connects to a domain name server & retrieves the corresponding IP address for the web server.
2. The web browser linked to the web server & sends an HTTP request (by means of the protocol stack) for the wished web page.
3. The web server receives the request & checks for the wished page. If the page exists, the web server sends it. If the server cannot determine the requested page, this will send an HTTP 404 error message. (404 mean 'Page Not Found' as anyone who has surfed the web possibly knows.)
4. The web browser receives the page back & the connection is closed.
5. Then the browser parses by the page and looks for other page elements it required to complete the web page. Usually these include images, applets, etc.
6. For each of the element needed, the browser makes added connections & HTTP requests to the server for each element.
7. While the browser has finished loading all images, applets, etc. the page will be loaded in the browser window completely.
Most Internet protocols are denoted through Internet documents known as a Request For Comments or RFCs. RFCs can be found at many locations on the Internet.
WWW is an Internet navigation tool which helps you to determine & retrieve information links to other WWW pages. The WWW is distributed hypermedia environment having documents from around the world. The documents are connected via a system known as hypertext, where elements of one document can be linked to particular elements of another document. The documents may be situated on any computer linked to the Internet. The word "document" is not restricted to text but may include graphics, video databases and a host of other tools.