A computer network is a collection of computers or computer-like devices (often referred to as nodes) that can communicate across a common transmission medium.
A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
Two nodes are said to be interconnected if they are able to exchange information. The connection can be via a copper wire; fiber optics, microwaves, infrared, and communication satellites.