Domain Name Server (DNS)
A Domain Name Server (DNS) is a database containing the necessary information to translate an Internet domain name (e.g. www.telecomabc.com) into its underlying IP-address.
Domain Name Servers (DNS) can be found throughout the Internet to make this translation. A DNS does not contain the information of the entire Internet. The DNS's are interconnected. If a DNS does not know the answer, it can ask another one.
Domain names are used because they are easier to remember than an Internet address.
DNS is also refferred to as Domain Name System.