whois in the host location

but there isn't a whitepaper or tutorial on the whois?

i'm studying the host location on a ip network,
and i have read that a possible solution is
the interrogation of a whois database.
For me is clear the use of a geographical DNS for
the position, but i don't understand the use 
of whois database for this issue.

please can you help me in this issue

Salvatore Loreto