Domain Basics

Domain basics include details of what a domain is; what it is used for; the different levels of a domain and important points to remember while choosing a domain name.

The Internet Protocol (IP) address is a machine readable numerical address assigned to every computer for communication on the Internet. The IP address is represented in 32-bit dotted decimal format, which contains a value between 0 and 255. A domain name is an IP address assigned in a human-readable form, composed of letters, digits and hyphens.

All domain names have corresponding IP addresses. Both of them are administered by Internet Assigned Numbers Authority. If you want to set up a website or want to create an e-mail id, then you require a domain name for representing yourself, your business, or brand on the Internet. Domain name is a part of the URL of a website. For example, URL is represented in the http://www.xyz.com format. The domain part of this URL is xyz.com. The content or length of domain names is subject to a minimum and maximum limit of 2 and 63 characters respectively.

Domains are divided into top level, second level and third level. The last part of the domain is called top level domain or TLD which is mainly classified into generic and country code top level domains. There is also a special top level domain called .apra which is only used for Internet infrastructure purposes. The most commonly used generic top level domain extensions are .com, .org, .net, and .info. Other popular top level domains are .edu, .gov, .mil, .biz, and .coop. Second-level domains are domains such as co.uk, .org.uk, .plc.uk, .ltd.uk, .edu.au and net.uk that come directly to the left of the dot in the top-level domains. Third level domains are sub domains which come below the second level domains.

Domain names must ideally reflect your business or brand name. They have to be registered through an authorized registry of ICANN. The chosen names should not cause any legal and technical problems such as copyright infringement, server problem etc.

For more information on domain basics, the official website of ICANN, http://www.icann.org, is the best resource.