DNS

The character based naming system by which servers are identified is known as domain name system(DNS).
Some most common domain names: com, edu, gov, net, org and co .

Web Browser And Web Server

The world wide web is based upon clients and server.
A www client is called Web Browser.
and a www server is called a Web server or just a server.

A web browser is a www client that navigates thru the World wide web and displays web pages .
A web server is WWW server that responds to the requests made by web browsers.