Domain Name System
DNS, the Domain Name System, is a distributed database that handles the mapping between host names,
which are more convenient for humans, and Internet addresses, which are 32-bit numbers
ranging between zero and a little over four billion (for IPv4; IPv6 uses 128-bit addresses, zero to about
1039). That is, it acts much like a phone book, so you can "call" www.wikipedia.com instead
of 64.78.205.6.
DNS also provides additional information, such as alias names for systems, contact information, and which
hosts act as mail hubs for groups of systems or domains.