How does JavaScript handle asynchronous programming?

It does asynchronous programming with callbacks, promises, and async/await syntax. Callbacks allow the making of a function callable only when some sort of task is finished, while promises do that in a more robust manner to handle asynchronous operations and, among other things, allow for more sophisticated error handling. Async/await syntax was added in ES8 and enables the writing of asynchronous code looking and working more like synchronous code, hence improving readability and maintainability.