DNS or Domain Name System is a system that points a domain name to physical IP address. For example, when a user types in www.example.com in their browser and hits enter, the DNS servers resolve it to the IP address where the website is hosted.
The purpose of DNS is to use easy to remember domain names for websites instead of their numeric IP addresses. It also enables website owners to change their web hosts without changing domain names. Website owners can simply change the DNS entry for their domain name and point to their new web host’s name servers.