Domain Names, DNS, and URLs

IP addresses are not convenient for users to remember easily. So an IP address can be represented by a natural language convention called a domain name.

Domain name system (DNS) translates domain names into IP addresses. DNS is the “phone book” for the Internet, it maps between host names and IP addresses. 

A uniform resource locator (URL) which is the address used by a Web browser to identify the location of content on the Web, also uses a domain name as part of the URL.