HTTP authoritative guide (i)-http overview

HTTP Overview

In the web, both browsers and servers communicate with each other through HTTP. So how does HTTP work?

First, the client sends an HTTP request to the server, and the server echoes the requested data in the HTTP response.

When the HTTP response occurs. Webserver appends a media type to all HTTP object data: The data format label for the MIME type (Multipurpose Internet Mail Extension). For example: Content-type:image/jpeg, which is a text tag that represents a basic object type and a specific subtype.

Each of the webserver resources has a name.    Known as the Uniform Resource Identifier (Uniform resource identifier), such as: http://www.baidu.com. There are two forms of URIs: URLs and urns. Most URLs follow a standard format, which includes three parts: a scheme (e.g. http://), an Internet address (such as www.baidu.com), a resource on the server (such as Image/banner.png), and today almost all URIs are URLs.

Next we analyze the contents of the HTTP request and the content of the HTTP response.

, there are examples of HTTP messages. Of Get is a method that tells the server what action to run.

200 is a status code for the HTTP response message, 200 means that the document returns correctly, 302 indicates redirect, redirects, gets resources elsewhere, and 404 means not Found. Unable to find this resource. The HTTP message contains three parts, starting line, header field, body

About HTTP is probably the above content, the following describes the TCP protocol. How to move from one place to another in the reading of the paper.

From the network layer. HTTP is at the application layer, and TCP is at the transport layer.

Before the client sends the message to the server, a TCP/IP connection between the client and the server needs to be established using the Internet Protocol (Protocol IP) address and port number.

such as: Http://207.200.83.29:80/index.html, where 80 is the port number.

Next is the structure component of the Web. This includes the agent (the HTTP intermediate entity between the client and server), the cache (the repository for HTTP). Enables frequent use of page denominations to be kept closer to the client), gateways (special webserver that connect to other applications), tunnels (special agents for blind forwarding of HTTP communication messages), Agent Proxy (semi-intelligent WebClient that initiates its own unsolicited HTTP request).

The structure component is also described in detail next.

HTTP authoritative guide (i)-http overview