Sandra E. Poindexter and Joan an Patrick Carey, The Internet Using Netscape Communicator Software, Thomson, 1998
STRUCTURE OF THE INTERNET
Networks can also be connected to each other to allow information to be shared between computers on different networks. The Internet, the largest and most famous example of a "network of networks," is made up of millions of computers linked to networks all over the world. Computers and networks on the Internet are connected by fiber optic cables, satellits, phone lines, and other communication systems, as shown [above].