Definitions for "Operational Amplifier"
A high gain DC amplifier that has a high input impedance and a low output impedance. Op-amps are the most basic type of linear integrated circuits.
An amplifier designed to perform computing or transfer operations and that has the following characteristics: (1) very high gain, (2) very high input impedance, and (3) very low output impedance. OpAmp Manufacturers
It is a high-gain, high-input impedance amplifier which performs mathematical operations when suitably wired, like integrated circuit.
Keywords:  solid
a solid state
Keywords:  good, example
a very good example