What is a com?

On the Internet a .com domain name, a top level domain (TLD) usually denotes a commercial website. While this analogy is not perfect , most all commercial web sites should use this TLD, but in certain cases, such as the .com TLD is not available, A TLD such as .net, or .biz can be selected for the commercial web site's domain DNS. The TLD .com can be used by a someone for other purposes, but it does help distinguish commercial websites from non commercial websites.