A mechanical, optical, or electronic system that performs a logical operation on an input signal.
A device, usually an electrical circuit, that performs one or more logical operations on one or more input signals. Logic gates are the building blocks of digital technology.
A collection of transistors and resistors that implement Boolean logic operations in a circuit. Transistors make up logic gates. Logic gates make up circuits. Circuits make up electronic systems. The truth tables and symbols follow. See Boolean logic.