Well, the idea is to insert two electrical signals into the inputs, so the output changes accordingly. This takes the difference between the inputs and amplifications, then the operational amplifier or the operational amplifier. You may have noticed that input A has a minus sign, and entry B has a plus symbol.
An operational amplifier (often op-amp or opamp) is a high gain electronic amplifier with a DC input and usually a single-ended output. In this configuration, an op-amp produces an output potential (relative to the mass circuit) that is typically hundreds of thousands of times greater than the potential difference between its input terminals.
The operational amplifiers came from analog computers, where they were used to perform mathematical operations in many linear, nonlinear, frequency dependent circuits.
The popularity of op-amp as a constituent element in analog circuits is due to its versatility. Due to the negative feedback, the characteristics of an operational amplifier circuit, its gain, input and output impedance, bandwidth and so on. They are determined by external components and have a small dependence on temperature coefficients or output variations of the actual amplifier.
Operational Amplifiers are today among the most widely used electronic devices, being used in a wide range of consumer, industrial and scientific devices. Many standard IC op-amps cost only a few cents in a moderate production volume; However, some integrated or hybrid operational amplifiers with special performance specifications may cost over $ 100. Small volume opamps can be packaged as components or used as more complex integrated circuit elements.
The operational amplifier is a type of differential amplifier. Other types of differential amplifiers include a fully differential amplifier (similar to an operational amplifier but with two outputs), the instrumentation amplifier (usually built by three operational amplifiers), an isolation amplifier (similar instrument amplifier but with voltage tolerance common mode that would destroy a normal operating amplifier) and a negative feedback amplifier (usually built from one or more operational amplifiers and a resistive feedback network).