Hypertext Transfer Protocol (HTTP)
In practical uses, HTTP is the protocol that allows text, graphics, multimedia, and other material to be downloaded from an HTTP server (commonly called a Web server). HTTP defines which actions clients can request and how servers should answer those requests. HTTP uses TCP as a transport protocol, making it a connection-oriented protocol. However, it can also use UDP for certain functions.
HTTP uses a uniform resource locator (URL) to determine which page should be downloaded from the remote server. The URL contains the type of request (for example, http://), the name of the server being contacted (for example, www.novell.com), and optionally the page being requested (for example, /support). The result is the syntax that Internet-savvy people are familiar with: http://www.novell.com/support. HTTP functions at the application layer of the OSI model.