Asynchronous JavaScript allows a program to perform long-running tasks—such as loading data from a server, reading files, or waiting for user actions—without stopping the rest of the code from running. Instead of blocking execution until a task finishes, JavaScript continues working and handles the result later when it becomes available.
JavaScript is single-threaded, meaning it can do only one task at a time. Without asynchronous behavior, slow operations would freeze the entire application. Asynchronous JavaScript solves this problem by using mechanisms like callbacks, Promises, and async/await, which enable JavaScript to manage time-consuming tasks efficiently.
In modern web applications, asynchronous JavaScript is essential for creating fast, responsive user experiences—allowing pages to load data in the background, respond instantly to user interactions, and update content dynamically without reloading the page.
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