DNS

A domain is the name of the website, such as "google.com" and "wikipedia.org". The DNS makes the Internet accessible to humans because it makes it easier to remember a web address as opposed to an IP address..

A domain is formatted as such: Top Level Domains, Second Level Domains, Third Level Domains, and Subdomains. Top Level Domains are the highest level domains such as .com, .edu, .org. Second level domains are directly below top level domains, and are formatted like ".com.edu". Third level domains are right under that, with a format like "example.com.edu". Subdomains are at the bottom of the hierarchy, formatted like "www.example.com.edu". Since this is the format of domains, you read domains from right to left.

The use of domains allows for a person to not know an IP address in order to visit a website.