The Domain Naming System is an easy way to find sites on the Internet without having to memorize long strings of characters.
Domain names fall into several different catagories, otherwise known as top-level domains.
Each top-level domain is controlled by a single organization who is responsible for the registration process. COM - Most businesses fall under catagory. This catagory is for Non-profit Organizations. NET - This is for Network Infrastructure machines. This domain is for Military Use.