Callbacks

Summary

Functions passed as arguments to be executed later — the original pattern for async code in JS, still used everywhere (event handlers, array methods). Callbacks remain fundamental because browser events and many APIs are callback-driven, even when Promises and async/await provide cleaner composition for asynchronous workflows.

• 1Write a function that accepts a callback and calls it after a `setTimeout`. Validate your understanding by applying it in a small practical example.
• 2Recognize 'callback hell' from deeply nested callbacks in older code. Validate your understanding by applying it in a small practical example.
• 3Understand why Promises/async-await were introduced to solve callback hell.