Quiescent current

Hi, another layman's question!

What is quiescent current?

Thanks.

In as plain English as possible, the current drawn by a device or circuit, while idling and doing nothing.

Think of a voltage regulator without any load, an audio amplifier without a sound signal, a microprocessor doing endless loops waiting for an input to be processed.

Current used when the circuit or device isn't actually doing anything.

I.e when the circuit is powered but not operating.

Thanks