When you are going to buy a new domain name you will need to choose among many extensions like .com .net .org .info and many more. Have you ever though why there are so many and what is the use of each one?
The extension of your domain name can attract more visitors, and make it look different or more professional. Those are small things, but they can do the difference.
.com (Commercial): It was created for commercial use.
.net (Network): It's purpose was to host sites of network companies, like phone/ internet/ television providers.
.ogr (Organization): This extensions was about to used by non-profitable organizations.
.biz (Business): It was created to give the idea of a business site when the .com was no longer a commercial extension.
I know there are much more, and many webmasters are not using the one which fits to their services. Although if you choose the right on you will see that your site will be looking more organized.