Определение и Значение "[pay] the piper"

What is the origin of the idiom "pay the piper" and when to use it?

The idiom "pay the piper" has its roots in the world of traditional folk music. It refers to the act of compensating a musician or piper for their performance or services. In a broader sense, it is used figuratively to mean that one must face the consequences or costs of their actions or decisions.