DNS

Domain Name Service. Not specific to FreeBSD; you can run DNS on Mac OS, Windows, just about any flavor of Unix. Essentially all DNS is is a translation service between IP addresses and Domain Names (e.g., "freebsdwiki.net"). The most ubiquitous DNS program is BIND; it is the default that comes with the Base system in FreeBSD, but it is not the only one -- see also djbdns or PowerDNS.