What’s a network? What’s an Internet?

Believe it or not, people used to once do useful work using computers that were not connected to other computers by any kind of communications network. No, I can’t remember how, either.

The first kind of computer network consisted of computers calling each other over the public telephone network. Some people would use a computer terminal, which wasn’t really a computer itself but something like a glorified typewriter to communicate over the telephone network, or fixed wires, with a real computer. Later when computers became common enough to place one on every desk, we began wiring those desktop computers together to create building-wide computer networks.

Still later, we connected those building networks themselves together into what we termed an Internetwork. During the 1980s we reached a point where it was possible to connect all the computers in the world into a global internetwork. Users began calling it simply, The Internet. `