# Callbacks

Node.js, being an asynchronous platform, doesn't wait around for things like file I/O to finish - Node.js uses callbacks. A callback is a function called at the completion of a given task; this prevents any blocking, and allows other code to be run in the meantime.

Visit the following resources to learn more:

- [@article@What are callbacks?](https://developer.mozilla.org/en-US/docs/Glossary/Callback_function)
- [@official@Asynchronicity in Programming Languages](https://nodejs.org/en/learn/asynchronous-work/javascript-asynchronous-programming-and-callbacks)