a famous circuit that amplifies the difference between two inputs
Operational amplifier. A high gain differential amplifier. Used extensively in analog circuits
An operational amplifier originally used in analog computers. They require positive and negative voltage sources and contain an inverting input, a non-inverting input and an output. Op-amps may be configured to operated many different ways.
Is a finished amplification step on a single chip. It's performance is similar to that of a transistor but the manufacturing costs are lower. It is part of the group of solid state amplifiers.