Your web browser is able to access a website when you provide the address bar a name with a proper extension. For example, you will be able to access the information on Yahoo by typing it (www.Yahoo.com) in your browser’s address bar. An IP is assigned to these human readable names that you type in your address bar to make the access easier for every domain name. A name combined with an extension (.com, .net, .org, co.uk etc) is known as a domain name. If a domain name has already been registered by someone else, you’ll not be able to use it unless the owner puts it up for the sale.