Technical articles:

HTTP: stateless and anonymous

HyperText Transfer Protocol (HTTP) is the fundamental means of exchanging information and requesting services on the Web. HTTP is also used when developing WAP services for mobile phone users and, with VoiceXML, also used to implement voice-controlled applications.
The most important thing to know about HTTP is that it is stateless. If you view 10 Web pages, your browser makes 10 independent HTTP requests of the publisher's Web server. At any time in between those requests, you are free to restart your browser program. At any time in between those requests, the publisher is free to restart its server program.

Here's the anatomy of a typical HTTP session:

user types "www.yahoo.com" into a browser
browser translates www.yahoo.com into an IP address and tries to open a TCP connection with port 80 of that address [TCP is "Transmission Control Protocol" and is the fundamental system via which two computers on the Internet send streams of bytes to each other.]
once a connection is established, the browser sends the following byte stream: "GET / HTTP/1.0" (plus two carriage-return line-feeds). The "GET" means that the browser is requesting a file. The "/" is the name of the file, in this case simply the root index page. The "HTTP/1.0" says that this browser would prefer to get a result back adhering to the HTTP 1.0 protocol.
Yahoo responds with a set of headers indicating which protocol is actually being used, whether or not the file requested was found, how many bytes are contained in that file, and what kind of information is contained in the file (the Multipurpose Internet Mail Extensions or "MIME" type)
Yahoo's server sends a blank line to indicate the end of the headers
Yahoo sends the contents of its index page
The TCP connection is closed when the file has been received by the browser

-r.c muthukumar(pandian saraswathi yadav engineering college sivaganga)