op amp ??
if yes
its an amplifier that is more than amplifier
it is definately used as amp but "operational" is coz u can perform various mathematical perations using it. such as +,-,/,*, log, exp
opamp are important
because we can use opamp as
amplifier - as inverting and non inverting
comparator - to compare two voltages
integrator - to intergrate
differentiator - to differentiate
filters - low pass,high pass and band pass
as oscillator
This is a VLSI technology that involves many BJTs & FETs in-built on a single chip. The main aim is to reduce the Size, Cost & the Complexity of the circuit. This is an IC called IC 741 which can invert your supply and can perform differentiation/integeration when necessary biasing is given.