What type of proxy is designed to be invisible to the end user, allowing connection to a server without their knowledge?

The correct choice is the transparent proxy, which operates without requiring any configuration or knowledge from the end-user. This type of proxy intercepts connection requests between the client and the server, forwarding them while remaining hidden in the communication process. Consequently, users may not even be aware that their requests are being processed through the proxy, as their experience is unaffected.

Transparent proxies are often used in environments like schools and businesses to monitor traffic, enforce policies, or cache data to optimize performance. Their invisibility facilitates seamless integration into existing networks, ensuring that users can navigate the internet without noticing any intermediary presence.

The other types of proxies serve different purposes: non-transparent proxies often require configuration on the client's side and provide a level of control over the communication process, while anonymous proxies offer some degree of privacy but may still be identifiable. Reverse proxies, on the other hand, serve to manage traffic coming to a server rather than dealing with clients directly, making them fundamentally different in function from transparent proxies.