An analog multiplier is a circuit that contains two inputs and one output.  The output signal equals the product of the two input signals.  Single quadrant analog amplifiers accept only unipolar signal inputs.  Two quadrant analog amplifiers accept one bipolar signal and one unipolar signal.  Four quadrant analog amplifiers accept bipolar signals on both inputs.

Most common analog amplifiers use mainly logarithm amplifiers and exponential amplifiers to realize the multiplication function because the sum of two logarithms equals the logarithm of the product.  The drawback of this structure is its limitation in bandwidth, which could be improved with a specific circuit called the Gilbert cell multiplier.

It is also possible to use a multiplier in conjunction with an op-amp to create an analog divider.