The main function of a proxy server in networking is to act as an intermediary between a client and other servers. When a client requests a resource from the internet, the proxy server intercepts this request and forwards it to the appropriate server. This setup offers various benefits, such as anonymity and privacy, as users' IP addresses are hidden. Proxies can also cache frequently requested content, enhancing performance and reducing bandwidth usage. Furthermore, they play a role in enforcing security policies, filtering content, and blocking access to harmful websites, thereby providing an additional layer of protection for users.