[ Thanks to Gandalf for this link.
]
“One of the most fundamental services on a TCP/IP network is
name service. It is the service that translates hostnames into IP
addresses. Linux systems use two techniques to convert hostnames to
addresses: the host table and the Domain Name System (DNS). The
/etc/hosts file is a table that maps names to addresses. It is a
simple text file that is searched sequentially to match hostnames
to IP addresses. The Domain Name System is a hierarchical,
distributed database system with thousands of servers across the
Internet, handling name and address queries. DNS is far more
important than the host table for the operation of the Internet,
but both services play a role.“Each entry in the /etc/hosts file contains an IP address and
the names associated with that address.For example, the host table
on our box might contain the following entries…”