Host names and uniform resource locators (URL) are resolved to Internet Protocol (IP) addresses by which of the following applications?

The resolution of host names and uniform resource locators (URLs) to Internet Protocol (IP) addresses is primarily handled by the Domain Name System (DNS). DNS serves as a crucial component of the internet's infrastructure, functioning like a directory that translates user-friendly domain names (such as www.example.com) into their corresponding numerical IP addresses (like 192.0.2.1). This process allows users to access websites without needing to memorize complex numerical addresses.

When you enter a web address into your browser, a DNS query is made to the DNS servers, which look up the domain name in their records and return the associated IP address. This translation is essential because network communication operates on IP addresses rather than human-readable names.

The other options serve very different purposes. For instance, Hypertext Transfer Protocol (HTTP) is the protocol used for transmitting web pages over the internet, but it does not handle the conversion of domain names to IP addresses. File Transfer Protocol (FTP) is specifically designed for transferring files between computers on a network, while Simple Mail Transfer Protocol (SMTP) is used for sending email messages. None of these protocols provides the name resolution functionality that DNS offers, highlighting why DNS is the correct application in this context.