Networks allow people to send messages and keep data accurate from one computer to another. It allows many users to have access to their data and manipulate it if needed and others can look at it. They do not need to be on the same computers to do this. However, a physical network address is needed too. This is a way of identifying the host of the network.
At one point, telephone numbers were used as the network address when people used dial-up for their internet. Now, people use wifi. A MAC address is known as a media access control address. It is different because it allows people who want to use wifi to be able to use it with a router.