The document defines the Internet as a set of computer networks around the world that are linked together through TCP/IP protocols, allowing thousands of users to access and share binary information. It is commonly described through analogies like a system of local and national telephone networks that form a huge international network. To connect to the Internet, one must first connect their computer to a telephone line via a modem, which then connects to their Internet provider's computer through another modem. The provider's computers are in turn connected to large host computers that function as servers, allowing the client computer access to all the services of the Internet once connected.