The Hypertext Transfer Protocol (HTTP) is the fundamental application layer protocol used for transmitting data over the World Wide Web. It defines the standardized methods and formats used by web clients (such as web browsers) to request resources and by servers to transmit those resources back. Operationally, the protocol dictates the structure of messages, managing the relationship between the requesting entity and the receiving server. This standardization allows diverse software applications and operating systems to communicate cohesively, making it the underlying mechanism that enables the global exchange of hypermedia documents and web services across networked systems.