How do you handle errors with callbacks vs promises vs async/await in JavaScript?

Callbacks are the original (deep nesting, manual errors). Promises flatten chaining with .then and .catch. Async/await makes async code look synchronous with try/catch. Async/await is built on promises; they can be mixed.

Use async/await for most modern code. It is more readable, easier to debug (better stack traces), and uses try/catch for errors. Use promises directly when you need Promise.all for parallel or complex chaining.

Yes. async/await is syntactic sugar over promises. An async function always returns a promise. await pauses until the promise resolves. You can mix await with Promise.all and other promise methods.