1. Something put into a system or expended in its operation to achieve output or a result, especially:
a. Energy, work, or power used to drive a machine.
b. Current, electromotive force, or power supplied to an electric circuit, network, or device.
c. Information put into a communications system for transmission or into a computer system for processing.
d. Any of the items, including materials, equipment, and funds, required for production.