The World Wide Web employs unique numbers called IP addresses and every single unit or website that is part of the Web features such an address. It is pretty difficult to remember to go to 188.8.131.52 to see a website though, that's why a much simpler structure was made in the 80s - domains. Each and every domain name contains a primary part and an extension, for example domain.com or domain.co.uk. Various extensions exist globally - part of them are given to countries, for example .co.uk in the abovementioned example, which is assigned to the United Kingdom, while many others are generic, like .com or .net. Some extensions are available for registration by every entity and others have certain requirements - company registration, regional presence, etc. You're able to get a new domain from a registrar organization such as ours and when the extension allows transfers, you'll be able to transfer an existing domain between registrars too.