The Hypertext Transfer Protocol, often known as HTTP, is a protocol for distributed, collaborative hypermedia information systems that functions as an application layer protocol inside the Internet Protocol Suite paradigm. The Hypertext Transfer Protocol (HTTP) is the backbone of data communication for the World Wide Web. Hypertext documents on the World Wide Web include hyperlinks to other resources that the user can easily access, for instance by clicking the mouse or tapping the screen in a web browser. HTTP is the foundation of this type of data communication.
Tim Berners-Lee started the development of HTTP in 1989 at CERN. The development of HTTP was summarised in a brief paper that described the behaviour of a client and a server while utilising the initial version of the HTTP protocol, which was designated 0.9.
The first version of the HTTP protocol quickly developed into a more complex variant, which served as the basis for the first draught of the eventual version 1.0 of the protocol.
A few years later, when the development of early HTTP Requests for Comments (RFCs) began, it was a coordinated effort between the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), with work eventually passing to the IETF. These RFCs were known as draughts.
1996 was the year that saw the completion and documentation of HTTP/1 (as version 1.0). It went through its first major revision in 1997 (as version 1.1), and then its specs were revised in 1999 and again in 2014.
More than 79% of websites already utilise the more secure version of HTTP, which is known as HTTPS.
HTTP/2 is a more efficient expression of HTTP's semantics "on the wire," and it was published in 2015. It is currently supported by almost all web browsers (96% of users) and major web servers over Transport Layer Security (TLS) using an Application-Layer Protocol Negotiation (ALPN) extension in situations where TLS 1.2 or a newer version is required. HTTP/2 is used by more than 46% of websites.
HTTP/3 is the successor to HTTP/2 and was announced in 2022; it is now supported by numerous web browsers (73 percent of users) and is utilised by 25 percent of all websites. Instead of TCP, the underlying transport protocol that HTTP/3 utilises is QUIC. As is the case with HTTP/2, it does not render obsolete any of the main versions of the protocol that came before it. Cloudflare and Google Chrome were the first to get support for HTTP/3, and now Firefox now has the capability to use it. If HTTP/3 is enabled on the server, real-world web pages load quicker than with HTTP/2 and even faster than HTTP/1.1, in some instances loading almost three times as fast as HTTP/1.1. HTTP/3 has lower latency than HTTP/2 (which is still commonly only enabled).