A proxy server is a network service that enables a client to access a target server indirectly through the proxy server. It acts as an intermediary between the client and the target server and helps the client obtain network information, control and register the forwarded notifications. The proxy server is primarily responsible for delivering legitimate network information between personal networks and Internet service providers.

The use of proxy servers offers several advantages, such as increasing access speed, hiding real IP addresses, and bypassing access restrictions. It can be utilized for various purposes, including connectivity, security, caching, content filtering, and access control. Proxy servers primarily operate at the dialog layer of the Open Systems Interconnection (OSI) model and play a crucial role in providing security functions offered by Internet link-level gateways.

When a client uses a browser to access a website, the browser sends a request signal to the proxy server. The proxy server then sends the request to the target website, receives the response signal, and transmits it back to the browser. A proxy server can improve browsing efficiency by caching web page content, so the browser does not have to send repeated requests to obtain the same information.

A proxy server has multiple functions, including accelerating web browsing speed, providing security filtering and flow control, and user management. It can also serve as a network firewall to enhance the security of the intranet network and address problems related to insufficient IP addresses.