HTTP proxy, full name Hypertext Transfer Protocol Proxy, is an intermediate server located between the client and the server. Its main function is to receive the client's request and forward it to the target server; at the same time, it will also receive the response returned by the server and return it to the client. Simply put, HTTP proxy is a transfer station for network information.

The function of HTTP proxy is far more than that. It also has a cache function that can store frequently accessed web page content. When multiple users request the same web page, the proxy can provide data directly from the cache, reducing the number of requests to the target server, thereby speeding up user access. In addition, HTTP proxy can also be used as part of a firewall to help block malware and attacks and improve network security.

The working principle of HTTP proxy can be divided into three steps: the client initiates a request, the HTTP proxy receives the request and forwards it, and the target server responds to the request and returns it to the HTTP proxy. In this process, the HTTP proxy will generate a new request header based on the client's request header information, which contains relevant information about the proxy server. When the target server receives the request forwarded by the HTTP proxy, it will generate a corresponding response based on the request content and return the response to the HTTP proxy. Finally, the HTTP proxy will send the response body back to the client and modify the response header information as needed.

HTTP proxies are widely used in various network activities. For example, in data scraping and online marketing, HTTP proxies can help us get more data. In web crawlers, HTTP proxies can disguise as different users to access the target website. In addition, HTTP proxies can also be used in browser settings.

Although HTTP proxies have many advantages, there are also some disadvantages that cannot be ignored. For example, using HTTP proxies may reduce the speed of Internet connection because the proxy server needs to process all traffic before sending it to the target website. At the same time, HTTP proxies also have security risks because the proxy server can see all user traffic, including passwords and other sensitive information.