DNS

The Domain Name System (DNS) associates various information (IP address, IPv6, Mail exchange servers, and much more...) with domain names.
Most importantly, it serves as the address book or the phone book for the internet by translating human-readable computer hosts (or hostnames), like www.dnsminer.com, into IP addresses, in this case 91.185.193.172 (A record), that networking equipment needs to deliver or fetch information. It also stores and provides other information (DNS records) such as the list of mail exchange servers that accept email for a given domain (MX records). In providing a worldwide keyword-based redirection service, the Domain Name System is an essential component of the internet. In the last years of the internet-boom it also serves as a load balancing tool and some effort has been made to make spam protection a part of the DNS (SPF and relay check databases which indireclty provide information through the DNS).