Internet domains are available for purchasing over the net and a person can easily purchase an internet domain which can be a top-level domain pertaining to educational institution or to the government. Most of the domains are followed by an extension name that can be .com or .org or .net and others. These extension names specify the purpose for which the domain is being used.
A person should be very careful while purchasing a web site domain from over the net. There are domain providers, also known as registrars who sell domains over the net. Internet domains are nothing but free spaces over the net that may be purchased to create and store your own web site. Each web site has a specific domain that designates its position over the net.
You can get the names of various domain providers when you search through the internet. However, before buying, always check whether the domain name, that you have specified has been brought by some one or not. You would require to give an unique name of your domain followed by the extension name. If the name of the domain matches with any similar names, then the site will specify you and would certainly inform you of the existence of such a domain. Existence of a domain means that the web space has already been purchased by some one else with that given name and hence you can never be authorized to use that space and the name of the domain for your purpose.
This is the only reason for which it is highly recommended that when you search over the internet for buying domains, then always perform a domain check whenever possible. It is natural that the name of your web site that you specify while buying may have already been used by some one else in this planet!