The Domain Name System (DNS) is responsible for translating human-readable domain names into machine-readable IP addresses. Whenever a user types a web address into their browser, DNS servers are queried to find the corresponding IP address of the web server hosting that site. DNS operates on port 53 and is a critical service for the functionality of the internet. The other options listed do not perform the function of translating domain names to IP addresses; DHCP assigns IP addresses to clients on a network, LDAP is used for accessing and maintaining distributed directory information services, and SNMP is utilized for network management and monitoring.