call-back

A callback is a programming technique where a function is passed as an argument to another function and is executed later, usually after a task completes. It allows programs to handle asynchronous operations, such as waiting for data from a server or a user action, without blocking the entire process. Think of it as providing a note to a colleague: "Please call me back when you're done," so your code knows what to do once an event or task finishes, enabling smoother and more efficient workflows.