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Hyper Text Transport Protocol

Protocol to move data between Web server and Web browser.
The Internet uses TCP/IP protocols. The Web uses sockets to communicate.
Socket: IP address + Port.
Each machine on the internet has an IP address (e.g., This IP address is augmented with another number called port. For example: (port is 80).
  • Server: a piece of software which perpetually "listens" to incoming connections (requests) on the given port. E.g.: Web Server, FTP server, Mail Server, SSHD server. Servers often operate on well known ports (< 1024).
  • Client: a piece of software which is called by the user to connect to some port/server. E.g.: Web browser, telnet command (client), ftp client. ssh client.
Web server is an application, i.e., piece of software which performs some specific function. Exchanges between Web server and Web browser have to be done in a very specific format called HTTP (currently version 1.1). There is a precisely defined format for requests (i.e., stuff which browser sends to server), and responses (i.e., stuff which server returns to a browser). Requests and reponses consist of TOP LINE, HEADER and BODY (BODY is sometimes absent).
HEADER and BODY are separated by an empty line.

Modified: Wed Feb 13 20:23:37 2002 GMT
Page accessed 2383 times since Mon Feb 3 15:33:12 2003 GMT