What is a Proxy server?

• A. a router that provides a gateway between users and the internet
• B. a firewall that blocks all external connections
• C. an email relay server
• D. a DNS resolver

Answer: (A)

A proxy server sits between your device and the resources on the internet, acting as an intermediary. When you send a request, it goes to the proxy first, the proxy forwards it to the target site, and then returns the response to you. Because it sits at the boundary between your network and external resources, it effectively provides a gateway for users to reach the internet. This positioning is what lets proxies offer benefits like caching (speeding up repeated requests), filtering or access control (restricting what you can access), and sometimes anonymous browsing by masking your real IP address.

The other roles described don’t capture this intermediary gateway function. A router routes packets between networks but isn’t primarily about handling user requests on behalf of clients. A firewall that blocks all external connections is about denying access, not mediating it. An email relay server forwards email messages. A DNS resolver translates domain names to IP addresses but doesn’t fetch web resources on behalf of users.