Hypertext Transfer Protocol (HTTP) is an application layer network protocol used for distributed, collaborative, and hypermedia information systems. Its use is mostly in retrieval of linked resources, called hypertext documents, which later formed the World Wide Web in 1990 by British physicist Tim Berners-Lee. Until now, there are two major versions of the HTTP protocol, namely HTTP/1.0 which uses a separate connection for each document, and HTTP/1.1 which can use the same connection to carry out transactions. Thus, HTTP/1.1 can be faster because it does not have to waste time making connections over and over again.
The development of HTTP standards has been carried out by the World Wide Web Consortium (W3C) and also the Internet Engineering Task Force (IETF), which led to the publication of several Request for Comments (RFC) documents, the most widely referenced being RFC 2616 ( published in June 1999), which defines HTTP/1.1.
HTTP is a request/answer protocol between client and server. An HTTP client (like a web browser or robot etc.), usually initiates a request by establishing a connection to a specific port on a specific Webhosting server (usually port 80). The client that sends the HTTP request is also known as the user agent. The server that responds, which stores resources such as HTML files and images, is also known as the origin server. Between the user agent and the origin server, there can be links, such as proxies, gateways, and tunnels.
HTTP is not limited to use with TCP/IP, although HTTP is one of the most popular TCP/IP application protocols over the Internet. Indeed HTTP can be implemented on top of other protocols over the Internet or over other networks. as mentioned in “implemented on top of any other protocol on the Internet, or on other networks.”, but HTTP requires a reliable transport layer protocol. Other protocols that provide such services and guarantees may also be used.
