HTTP Communicaton Protocol

HyperText Transport Protocol or HTTP is a communication protocol that is used to request and transmit files over the Internet and other networks.

HTTP is the primary method for exchanging information over the world wide web.  Because most web browsers default to the HTTP protocol, it is normally not necessary to enter "HTTP://" when requesting a web page.

World Wide Web - Conceptual Overview

In response to a HTTP request from a web browser, the web server responds by returning a status code (e.g. "200 OK") and one or more requested files.

The files returned could be html pages, graphics or scripts for applets that the web browser would then assemble and display the web page.