Which service resolves human-readable hostnames to IP addresses?

• A. DHCP
• B. NAT
• C. DNS
• D. ICMP

Answer: (C)

Humans use names to identify resources, but networks must use numbers to route traffic. The Domain Name System translates those human-friendly hostnames into the IP addresses that devices use to reach each other.

A DNS lookup starts when a device asks a resolver to find the IP for a name. The resolver may query the root servers, then the top-level domain servers, and finally the authoritative servers for the exact domain, until it gets the IP address back. That result is then cached to speed up future lookups. This is why you can type a name like www.example.com and your device can connect without you needing to remember the numeric address.

Other services have different roles: DHCP assigns IP addresses to devices on a local network; NAT maps private addresses to a public one for Internet access; ICMP handles diagnostic and control messages used by tools like ping.