W3C webarch section/Protocols

Protocols are the languages that programs and devices use to “talk” to each other. At the foundation of the Web lies HTTP, the Hypertext Transfer Protocol. It is the basic protocol for exchanging Web pages and related information around the Internet. W3C also defines the SOAP protocol that can be used to build more sophisticated services on top of the Web.

What is HTTP?

HTTP is a protocol for exchanging bundles of information between a client (such as a Web browser) and a server. It was originally devised for HTML pages and related content like images. Every time you open a Web page or submit a form, your browser makes HTTP requests to the Web site. But its generic nature makes HTTP suitable for many other purposes, such as retrieving stock quotes or weather forecasts in an automated fashion. It is one of the most widely used protocols of the Internet.

What is SOAP?

SOAP is a protocol for exchanging structured XML messages between applications. It enables a particular way of tying applications together, known as remote procedure call. Many Web services are built this way. SOAP addresses a number of concerns that are common to this kind of systems — such as message structure and data typing — making it easier to build them. SOAP messages are usually transferred over HTTP.

Current Status of Specifications

The development of HTTP is headed by IETF, the Internet Engineering Task Force. Their ongoing effort at refining the HTTP specification is known as HTTPbis. The previous, established revision is HTTP/1.1, defined in RFC 2616.

For information on SOAP, see SOAP Current Status.