Internet

All networks fundementally consist of either a Centralized, Decentralized, or Distributed design. An Internet is the connection of two or more of these networks together.

The Internet is a series of networks interconnected, consisting of individual services. The Internet has evolved out of several historical networks, the most significant of which was the ARPANet, a network connecting both American Universities to each other and also connecting the MILNet together (a network existing for US Military use).

A single network is not an Internet. An Internet must have multiple networks connected to each other, else it is simply a network.