What is http

HTTP is a hypertext transfer protocol and the most widely used network protocol on the Internet. All WWW files must comply with this standard.

HTTP is an application layer protocol. Like other application layer protocols, it is a protocol for implementing a certain type of specific application, and its functions are implemented by an application running in user space. HTTP is a protocol specification. This specification is recorded in the document and is the implementation program of HTTP that actually communicates through the HTTP protocol.

HTTP operating mechanism:

HTTP protocol is based on the request/response paradigm. After a client establishes a connection with the server, it sends a request to the server. The format of the request is a uniform resource identifier, a protocol version number, followed by MIME information including request modifiers, client information and possible content.

After receiving the request, the server will give corresponding response information. The format is a status line including the protocol version number of the information, a success or error code, followed by MIME information including server information, entity information and possibly Content.

In fact, to put it simply, in addition to HTML files, any server also has an HTTP resident program for responding to user requests. The browser is an HTTP client and sends a request to the server. When a start file is entered in the browser or a hyperlink is clicked, the browser sends an HTTP request to the server. This request is sent to the URL specified by the IP address.

The above is the detailed content of What is http. For more information, please follow other related articles on the PHP Chinese website!