How many inputs does an op-amp typically have?

An operational amplifier (op-amp) typically has two primary inputs, which are referred to as the inverting input and the non-inverting input. The inverting input is marked with a minus sign (-), while the non-inverting input is marked with a plus sign (+). These inputs allow the op-amp to amplify the difference in voltage between them, which is a fundamental characteristic of its operation.

The configuration of having two inputs enables various applications, such as subtraction, summation, and amplification of signals. This dual input design is what makes op-amps versatile components in analog signal processing circuits.

While there may be op-amp configurations or types (such as differential amplifiers) that involve additional terminals (like offset or power supply terminals), the core operation is fundamentally based on the interaction between the two main inputs.