Internet domain or extension is a unique name that identifies a website on the Internet.
The main purpose of domain names on the Internet and the domain name system (DNS), is to translate the IP addresses of each asset in the network, to memorizable and easy to find terms. This abstraction makes it possible for any (network) service to move from one geographical location to another on the Internet, even when the change implies that it will have a different IP address.
Without the help of the domain name system, Internet users would have to access each web service using the IP address of the node (for example, it would be necessary to use http://18.104.22.168/ instead of http://google.com). In addition, it would reduce the number of possible websites, since currently it is usual for the same IP address to be shared by several domains.