For most users, the important thing to remember about the Internet is that it is the means by which you can access and communicate with many other computers worldwide. You don't need to know how many or which phone companies have to work together to make the connection or what equipment they use. The Internet works in the same way. In order to make this world-wide communication possible, every computer on the Internet has to have a unique address. This address is called the IP address.
Most computers also have a name, which is comprised of a machine name and a domain name.
For example, 128.138.129.2 is the IP number for spot. EDU , where spot is machine name and Colorado. EDU is the domain. Many different organizations and people are connected to the Internet. Universities and research institutions around the world make up a large portion.