The term OP-AMP is used to denote an amplifier which can be configured to perform various operations like amplification, subtraction, differentiation, addition, integration etc.
An operational amplifier or OP-AMP/OPAMP is a DC-coupled voltage amplifier with a very high voltage gain. Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices.
The integrated op-amp’s offers all the advantages of IC’s such as high reliability, small size, cheap, less power consumption. They are used in variety of applications such as Inverting & Non-inverting amplifiers, Unity gain buffer, Summing amplifier, Differentiator, Integrator, Adder, Instrumentation amplifier, Wien bridge oscillator, Filters etc.