These are the domains that started it all. .com is the most well known TLD of them all. It was originally intended for commercial (get it?) use, but in the past few years it has seen massive growth for all types of use. .com domains are harder to come by these days, but are still recognized internationally as the business domain. If a .com for your business is not available, be sure to check out the up and coming .biz

.net & .org also started out with with specific uses in mind. >net was to be used for networks such as ISP's, Hosting company's etc. .org was created for non-profit organizations. Once the .com explosion happened, people started registering these names as well, just to get their name on a domain no matter what extension it used. These domains are in limited supply now, but there are still thousands being registered daily.

So what are you waiting for? Register your domain name today, before it's too late!