What is meant by the term op-amp offset voltage?

An operational amplifier (op-amp) ideally has zero volts at its output when the voltage difference between its input terminals is zero. However, due to internal manufacturing mismatches, a small voltage difference always exists. This is known as the input offset voltage. The offset voltage is effectively the differential DC voltage required between the inputs to force the output to exactly zero volts. Because an op-amp's open-loop gain is enormously high, any tiny offset would immediately saturate the output if left open-loop. Therefore, this potential between the amplifier input terminals is practically defined and measured in a closed-loop condition. Distractors that mention subtracting the input from the output or referencing the next stage are incorrect because offset voltage is strictly an input terminal characteristic. The open-loop option is incorrect because the amplifier's extreme gain makes it impossible to stabilize and measure the offset without a feedback loop.