Design patterns·Wiring: injection, containers and lifetimes
you register your code and something else decides when it runs, which is the opposite of how a library feels.
Hollywood principle
Also calleddon't call us, we'll call you
The one-line statement of inversion of control: don't call us, we'll call you. It is the distinction between a library, which you call, and a framework, which calls you, and it is what template method, observers and lifecycle hooks all have in common. Useful mostly as a way to explain inversion of control in a sentence someone will remember.