Basic DNS

The domain name system (DNS) is an application-layer protocol for mapping domain names to IP addresses. It serves as a phone book for the Internet, so computers can look up for IP addresses from domain names. Humans are good at memorizing compute names, such as www.google.com, www.gmail.com etc., but computers need IP addresses in order to communicate with one another. Therefore, given a name, a computer needs to find out the corresponding IP address, before it can communicate with the intended computer. Translating names to IP address (and vice versa) is primary task of the Domain Name System (DNS).