Final answer:
DNS is the service that resolves FQDNs to IP addresses. It is essential for how the internet operates, allowing users to reach websites using domain names instead of IP addresses.
Step-by-step explanation:
The type of service that performs an FQDN-to-IP resolution is DNS (Domain Name System). DNS is a protocol within the set of standards for how computers exchange data on the internet and on many private networks, known as the TCP/IP protocol suite. Other services like HTTP, SMTP, and FTP rely on DNS to map human-friendly domain names to IP addresses that are used by computers to identify each other on the network.