There are also country code top level domain extensions (cctlds). Some examples of these are .us (USA), .cn (China), .in (India), .de (Germany), and .co.uk (UK). .TV (Tuvala) is also a country code extension but it is often sold as a general tld.

The most common and well known tld is .com. .Com was first extension to be used extensively by businesses online. It is considered by many to be king of all tlds because of how recognizable it is, clout it's use offers and because it is extension most likely to be typed-in (people will actually type .com domain name in their browsers to go directly to site even if they are not familiar with an actual site that may be there - this is free traffic in a sense). This can occur because people may assume all sites end in .com or that .com somehow is part of any name or it can occur due to "bleed" from other tlds - people see a name with some extension and when they go to look for it or type it in, they put .com instead. For many, .com truly is internet.

.Net has generally seen less use than .com, but many still consider it to be second most valuable extension. Many isps do use it. .Org is used by many non profits, various organizations and government related sites. Considered by some to be second or third most valuable tld, in terms of recognition and resale price level. .Com, .net and .org are original general use internet tlds. They are sometimes collectively referred to as CNO. They have been with us since mid/late 80's.