Which protocol typically uses UDP Port 53?

The protocol that typically uses UDP Port 53 is DNS, which stands for Domain Name System. DNS is crucial for translating human-readable domain names, like www.example.com, into IP addresses that computers use to identify each other on the network.

Using UDP (User Datagram Protocol) allows DNS to send queries and responses quickly and efficiently, which is ideal for the nature of DNS transactions that often require rapid request and response communication. Since DNS queries are usually small and sent in batches, using UDP reduces the overhead associated with establishing connections compared to TCP (Transmission Control Protocol).

Other protocols mentioned, such as HTTP, FTP, and SMTP, use different ports: HTTP typically uses TCP port 80, FTP uses ports 20 and 21, and SMTP uses TCP port 25. These protocols have different functional purposes and utilize reliable connection-oriented communication, making them unsuitable for the quick lookup tasks that DNS handles via UDP on port 53.