Which protocol operates on UDP port 53?

The Domain Name System (DNS) operates on UDP port 53. DNS is essential for converting human-readable domain names (like www.example.com) into IP addresses that computers use to identify each other on the network. This translation process is crucial for the functioning of the internet and various services that rely on domain name resolution.

UDP, or User Datagram Protocol, is a connectionless protocol that allows for faster transmission of data since it does not require establishing a connection before sending the data. This makes it well-suited for the DNS queries that are typically brief and require quick responses.

In this context, the other options involve different protocols that use distinct ports for their operations. For example, Network File Share utilizes a combination of protocols and ports, Simple Network Management Protocol uses port 161, and Network Time Protocol operates on port 123. These distinctions further highlight why DNS is specifically associated with UDP port 53.