DNS in the Internet

DNS is  a protocol that can be used in different platforms.

In the Internet the Domain Name Space is divided into three different sections :

1) Generic domains

2) Country domains and

3) The Inverse domains

1) Generic domains:-
The generic domains define registered hosts to their generic behavior.

Generic domain labels are as follow:-

aero :-   Airlines and aerospace companies

biz    :-   Businesses or firms

com   :-   Commercial organizations

coop   :-  Cooperative business organizations

 edu    :-  Educational institutions

gov      :-  Government institutions

info     :-   Information service provides

int       :-  International organizations

mil      :-  Military groups

museum :- Museums  and other non profit organizations

name    :-  Personal names (individuals)

net      :- Network support  centers

org     :-  Non profit organizations

pro     :-  Professional individual organizations


2) Country domains:-
The country domains section uses two - character country abbreviations.
Example :-
us  :-  United States

in  :-   India

uk  :- United Kingdom

Second labels can be organizational ,or they can be more specific , national designations.
The United States ,for example , uses state abbreviations as a subdivisions of us example ca.us


3) Inverse domains:-
The inverse domain is used to map an address to a name .the convention of reading domain labels from bottom to top ,an IP address such as 132.34.45.121 is read as 121.45.34.132.