What device translates domain names into IP addresses?

The correct choice is the DNS server because its primary function is to resolve domain names into IP addresses. When a user inputs a domain name into a web browser, the DNS server is responsible for translating that human-readable address (like www.example.com) into a numerical IP address that machines use to identify each other on the network. This process enables the user to access the desired website without needing to remember the specific numerical address.

A router, while essential for directing data between different networks, does not perform the role of translating domain names. It primarily manages data traffic and routes information based on IP addresses. A hub is a basic networking device that connects multiple Ethernet devices to a network but lacks intelligence for resolving domain names. A firewall protects a network by controlling incoming and outgoing traffic based on predetermined security rules but does not handle domain name resolution. Thus, the DNS server is the specific technology designed for this translating task.