Domain name extensions are .com, .net, .biz, and .info, they all follow the first part of a domain name.
Two more real life examples for you.
BlogBoogie.com
BlogBoogie.net.
The .net and the .com are the domain name extensions.


I want to bring this up because one guy I know purchased a .com domain name for his Blog and built it up over the years. Someone came along and used a .net riding off the success of the .com guy. What a ripoff! Not nice.

Solution? When I started BlogBoogie I purchased both the .com and the .net. Not only does this stop people ripping off ones hard work and domain name brand, there is a spare domain name parked for future growth.