DNS is the name given to the Internet's "phone book". When you visit a website such as support.dolitl.com (the address is also known as a domain, or host name), your computer needs to translate that address into an IP address. The IP address is the Internet address of the computer or server that stores web pages for that website, much like a telephone number is "your" address on the telephone network.

To translate the domain name, your computer uses DNS to look up a domain's IP address up with a DNS server.