Hyper-Text Transfer Protocol (HTTP)

Hyper-text Transfer Protocol (HTTP) is a communication protocol that facilitates the transfer or retrieval of linked documents across the internet. HTTP runs over the Transmission Control Protocol (TCP) and is used for communication between web clients and web servers. It is considered as the foundation of data communication for the World Wide Web.

HTTP was developed in 1989 by Tim Berners-Lee, a British computer scientist, at the behest of CERN, the European Organization for Nuclear Research. It is an application-level protocol that provides a way for visitors to interact with websites, and a way for web servers to respond to requests from visitors. It enables web clients (e.g., a web browser) to send and receive hypertext-based data to and from a web server.

HTTP messages are formatted in plain text and can contain text, images, audio, and video files. An HTTP message typically consists of a start line, one or more header fields, an empty line, and an optional message body. The message body contains the data transmitted from the client to the server, while the header fields contain additional information such as content type, content length, and transport encoding.

HTTP supports a number of methods of communication, including GET, POST, PUT, HEAD, and DELETE, among others. Each method describes an action to be taken by the web server in response to the request message sent by the client.

HTTP is an important protocol for the Secure Sockets Layer (SSL) protocol, which is commonly used to provide secure communication between websites and clients. By using SSL protocols, both the client and server can authenticate each other, prove their identities, and encrypt the communication sent between them.

HTTP is used extensively in web development, and is the application protocol most often used for web-based applications. Additionally, it has become the primary protocol for data transfer in modern cloud computing and online services.