DNS stands for Domain Name System. It is a hierarchical distributed naming system for computers, services or any resources connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. 

The different functions of DNS are as follows: 

• It translates meaningful domain names into the numerical IP addresses, which is needed for the purpose of locating computer services and devices worldwide. 

• It serves as the phone book for the Internet by translating human-friendly computer hostnames into IP addresses. 

• The DNS can be quickly updated, allowing a service’s location on the network to change without affecting the end users. 

• It distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating authoritative names servers for each domain. 

• It also specifies the technical functionality of database service. It defines the DNS protocol, a detailed specification of the data structure and data communication exchanges used in DNS, as part of the Internet Protocol Suite (IPS).