An insulated cable with the conducting element made of metal or glass. A wire may refer to an electric cord that plugs into a wall outlet. In a computer network, wires generally refer to Ethernet cables. A wire may also refer to the USB cable between a computer and monitor, keyboard or mouse.
The phrase "over the wire," which dates back to the telegraph in the 1800s, means transmitting signals from one entity to another. However, today, the transmission medium is often wireless and not a metal or glass wire. See
twisted pair,
Ethernet,
USB and
wireless.