Topic summary
Hosts file

Extracted from the Wikipedia article Hosts (file).
Purpose
In some operating systems, the contents of the hosts file is used preferentially to other name resolution methods, such as the Domain Name System (DNS), but many systems implement name service switches, e.g., nsswitch.conf for Linux and Unix, to provide customization. Unlike remote DNS resolvers, the hosts file is under the direct control of the local computer's administrator.