From LQWiki

A Hostname is the name given either to localhost, a computer on a LAN, or a node in the DNS hierarchy.

To find out your hostname, use the following command:

$ uname -n

or

$ hostname

The hostname of a computer can be changed in several different ways. In Red Hat, to permanently change the hostname, modify the HOSTNAME value in: /etc/sysconfig/network

To immediately (but not permanently) change the hostname:

$ hostname newhostname

See also

• http://en.wikipedia.org/wiki/Domain_name
• DNS
• hosts file