A proxy firewall acts as an intermediary between a user's device and the internet. It receives requests from users, forwards them to the desired web server, and then sends the server's response back to the user. This process helps to hide the user's IP address, enhancing privacy and security. In addition to privacy, a proxy firewall can filter content and block access to certain websites. It can also cache frequently accessed web pages, improving load times for users. By controlling the flow of data, a proxy firewall helps protect networks from potential threats and unauthorized access.