Promises
Promises are a programming pattern and language feature used to handle asynchronous operations in JavaScript and other languages. They represent a value that may be available now, in the future, or never, providing a cleaner alternative to callback-based asynchronous code. Promises allow developers to chain operations and handle success or failure states in a more structured way.
Developers should learn Promises to manage asynchronous tasks like API calls, file I/O, or database queries without falling into 'callback hell'. They are essential for modern web development, especially when working with frameworks like React or Node.js, as they enable better error handling and code readability. Promises are also the foundation for newer async/await syntax, making them a prerequisite for advanced JavaScript development.