Before you can send a letter to someone or your friend, you need to know his/her mailing address. If you want to visit a website, you also need to know its 'address', this address is called Domain name. Here are some examples of domain names given bellow.

academictutorials.com

Google.com

vyom.com

vyomworld.net

Linux.org

Yahoo.co.uk

Natalie-Portman.ws

Domain name is not case sensitive, which means that academictutorials.com, AcademicTutorials.com and AcaDemicTuTorials.coM are the same. A dot act as a separator in a domain name. The part after the last dot is called the Top Level Domain (TLD).

Domain name registrations for the most seen as dot extension .com, .net, .org are unrestricted and are opened to everyone. They are usually referred to as International TLDs. When the internet started some year ago, it is recommended that most of the companies should use .com, internet service providers should use .net and organizations should use .org. But today, this rules are no longer engaged and you can register under any international TLDs which you want.

Other international TLDs include .aero use most of the air-transport industry, .biz for the businesses, .coop for the cooperate .info for all uses, .museum for museums, .name for individuals use, and .pro for professions use. But they are not as popular as .com, .net and .org.

Two letter domains , such as .in repersent India , .uk for United Kingdom , .us United State and .jp (Japan) are referred as country code Top Level Domains (ccTLDs) and are corresponded to a country, territory, or other geographic location. The rules and policies for registering domain names under the ccTLDs vary significantly and some are reserved only for the citizens of the corresponding country.

A subdomain is also known as a "third-level" domain, and is a great way to create memorable web addresses for various areas of your web site. For instance, Yahoo! uses subdomains for its services, i.e., mail.yahoo.com, music.yahoo.com, search.yahoo.com etc. You can create subdomains for co-workers, family members, or to build separate sub-sites.

Subdomain services are usually offered through the web host, not directly through the domain registrar. If you are interested in creating subdomains from your main domain name look for a web host that supports or offers subdomains.

This is main domain www.yoursite.com and mysite.yoursite.com is sub domain of www.yoursite.com.

1. Your domain name is not too large because People do not like to type longer! The shorter your domain, the easier it is to reach and the less are the chance the user will make a typographical error while user typing your domain name.

2. Your domain name is Meaningful because it is easy to enter or remember. Select a domain that relates to your site in a way that people will understand.

3. Clarity is important when you choose a domain name. You should avoid selecting a name that is difficult to spell or pronounce,for example www.autrep.com.This domain name not follow the previous rule.