Domain name is the unique name that you choose for your web site. Web sites in the World Wide Web have their names and are identified by the domain names that correspond with numeric IP address.
By the following example we will illustrate the difference between URL and domain name:
URL: http://www.a touch.com/index.html
Domain name: www.a touch.com
Registered domain name: a touch.com
A complete domain name consisting of a host, the second-amount domain, and the top-amount domain is called FQDN (fully qualified domain name). For example, www.a touch is a FQDN, where www is the host; something is the second-amount domain; and .com is the top-amount domain.
A top-amount domain (TLD) is the last part of an Internet domain name; that is, the letters that follow the final dot of any domain name. For example, in the domain name www.website.com, the top-amount domain is .com (or COM, as domain names are not case-sensitive).
There are several types of domain names:
gTLD (generic top amount domains) such as .com, .net, .org, .name and others
ccTLD (country code top-amount domains) also called as regional domain names, for example: .fr, .it, .de, .eu, .nl, .be, .ru and others.
The company that is registering the domain names is called registrar, the person who registers domain name is called registrant.
When you register domain name it is recommended that you pay attention on the actual registrant of your domain name as some companies register domains on their names.
Domain name is permanently registered for a certain period; it is called domain name registration period
For most of domain names the minimal registration period is one year
Though for some domains (for example .uk, .mobi, .us) the minimal registration period is 2 years.
The date when domain name was registered is called registration date
Depending on the registration period, the domain name will have expiration date
Example: domain name was registered on 1st of April 2006
It was registered for 1 year
Thus domain name expiration date will be 1st of April 2007
It is permanently recommended that customers keep in mind their domain name expiration date and renew domain previous to domain expires in order to exclude any sort of downtime
The information about the registrant of the domain name and its registration period are normally showed in Whois database. Using Whois database you can determine whether domain name is available for a new registration or is by now registered/taken, can determine the registrant (owner) of the domain name, domain name registration and expiration dates, IP address assigned to the particular domain name.