HTTP (Hypertext Transfer Protocol) is a communications protocol used for information transfer on the World Wide Web. It enables a client (e.g. a web browser, crawler, or even a web application) to communicate with a server by sending requests and receiving responses to those requests. Those responses may, but don't have to, contain resources requested by the client, such as HTML pages, images, stylesheets or binary files.
Connection between the client and the server can optionally be secured with the use of the https (HTTP Secure) protocol, which encrypts all information transferred, as well as establishes the identity of the server.
Other protocols that HTTP relies on include:
Protocols similar to HTTP include: