Asynchronous programming in JavaScript allows code to run in a non-blocking manner, enabling more efficient execution and smoother user experiences. At the heart of this approach are promises and async/await. A promise is an object representing the eventual completion (or failure) of an asynchronous operation and its resulting value. Promises can be in one of three states: pending, fulfilled, or rejected. They offer methods like .then() and .catch() to handle successful results or errors, respectively.

Async/await, introduced in ES2017, provides a more readable and concise way to work with promises. By marking a function with the async keyword, you can use the await keyword inside it to pause the function execution until the promise settles, effectively writing asynchronous code that looks synchronous. This makes handling asynchronous operations easier and more intuitive, reducing the need for chaining .then() calls and improving error handling with try/catch blocks. Together, promises and async/await represent a powerful toolkit for managing asynchronous tasks in modern JavaScript.