A proxy server is basically a computer that acts as an intermediary and allows a client to make requests to other servers in the global network. The proxy server interaction scheme is simple:
- A client connects to the proxy server.
- A client requests a particular website.
- Further, the proxy server does one of the following: connects to the server on which the resource is located or provides this resource from the stored cache.
Why do we need proxies?
- To hide user data. The proxy server anonymizes access, preventing third-party services from detecting the client’s IP address.
- To compress data. The proxy serves to save the use of external traffic. As part of the compression algorithm, information is compressed and transmitted to the end user.
- To cache information, as was mentioned above. It is necessary for the optimization of the proxy server and reducing the load on the channel. Caching is used for regular requests to specific resources.
- To secure the local network. The proxy server can be configured so that all computers connected to the local network can access sources through it. This measure also works in the opposite direction – external services will not be able to access computers on the local network, but they may send requests through proxies.
- By using a proxy server, you can block access to certain sites or bypass blocked sites or web pages.
Types of proxy servers
- HTTP proxy servers receive HTTP traffic. They are characterized by fast operation, determined by the lowest ping value (measured in milliseconds). They are also great for web surfing.
- HTTPS proxies support SSL, use low-level TCP along with the high-level protocol, which allows you to work with almost any network application. They are distinguished by a high level of anonymity due to the support of the CONNECT method.
- SOCKS servers use OSI models to ensure independence from FTP, HTTP, POP3, and other high-level protocols, making it possible to pass any traffic. The latest version of SOCKS 5 (there are also SOCKS4, SOCKS4a, and SOCKS5) supports TCP/IP and UDP/IP protocols.
- Web proxies are best known as anonymizers. The most popular of these is the CGI (Common Gateway Interface). With their help, without installing the program on the computer, you can go to a special web form and open a specific page of the resource you’re interested in. CGI proxies use HTTP and FTP with support for JavaScript, Flash, and SSL.
