---------------------------------------------------------- Permission is granted for below article to forward, reprint, distribute, use for ezine, newsletter, website, offer as free bonus or part of a product for sale as long as no changes are made and byline, copyright, and resource box below is included. ---------------------------------------------------------- What is DNS?By Stephen Bucaro
Have you ever wondered what happens when you enter, or click on, a web address in your browser? How does your computer connect to Web site you requested? Part of what makes that happen is Internet's Domain Name Service (DNS).
Similar to how every telephone has a unique number, every Web site, or "domain" on Internet has a unique Internet Protocol (IP) address. IP addresses are 32 bit numbers represented by four bytes separated by dots. Each byte can represent a number from 0 to 255, therefore highest IP address 255.255.255.255.
People have difficulty remembering 12 digit numbers, so web sites are are identified by names like www.sitename.com instead of their IP address. DNS is a database of domain names and their corresponding IP addresses.
In beginning, every computer on Internet had a list of all domain names and their corresponding IP addresses. But that quickly became unwieldy. Now domain name database and domain name to IP address translation is performed by computers assigned as DNS servers.
Each DNS server has data only about domains it is serving. When a computer makes a request to its DNS, it is possible that DNS server doesn't have data required to answer request. Special "root name" servers hold a list of DNS servers for top-level domains, like .com, .org, .edu etc. For example, top-level DNS for .com lists DNS servers for domain names ending in ".com".