HTTP

HTTP, in full HyperText Transfer Protocol, standard application-level protocol used for exchanging files on the World Wide Web. HTTP runs on top of the TCP/IP protocol and (later) on the QUIC protocol. Web browsers are HTTP clients that send file requests to Web servers, which in turn handle the requests via an HTTP service. HTTP was originally proposed in 1989 by Tim Berners-Lee, who was a coauthor of the 1.0 specification. HTTP/1.0 (released in 1996) was “stateless”: each new request from a client established a new connection instead of handling all similar requests through the same connection between a specific client and server. HTTP/1.1 (released in 1997) includes persistent connections, decompression of HTML files by client browsers, and multiple domain names sharing the same IP address. HTTP/2 (released in 2015) was designed to solve problems with slow page loading and was a binary protocol in which binary values were used instead of plaintext as in previous versions. HTTP/3 relies on the faster QUIC protocol instead of TCP and, as of early 2022, was not yet released in final form but was supported by most browsers. In the 2010s many websites began using HTTPS (Secure HTTP), developed in 1994 by Netscape Communications Corporation and in which the SSL (Secure Sockets Layer) protocol was added to HTTP to provide a layer of encryption between browsers and servers.