DNS stands for Domain Name System. The Internet contains millions of websites stored on servers with IP addresses. Since IP addresses are difficult to remember as they are in terms of numbers or strings, each computer server hosting a website is given a name against its IP address. These names are called Domain names or hostnames. DNS can be considered as a phonebook where instead of remembering phone numbers, we assign names to them.

A DNS server is a server that maintains a database of domain names and their corresponding IP addresses. The conversion of the domain name of each web server to its corresponding IP address is called domain name resolution, which is done through the DNS server. When we enter a URL on a web browser, the HTTP protocol approaches the DNS server to obtain the IP address corresponding to that domain name.