The Simple DNS Zone Editor allows website owners to create and manage A records and CNAMEs for their website. The Domain Name System (DNS) is the service that takes a name, such as sample.tld, and then turns it into an IP, like 127.0.0.1. The best analogy for DNS is a phone book: where with a name, a phone number can be obtained.
A Records are a name that turns into a number. CNAMEs are a name that turns into another name, the client will then continue on the path with the new name.