Linux Name Services
Source: Linux Exposed
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.
