Zone.js

Zone.js is a JavaScript library that provides execution contexts for asynchronous operations, enabling better error handling and performance monitoring. It creates zones that persist across asynchronous tasks, allowing developers to track and manage the execution flow of complex asynchronous code. The library intercepts browser APIs like setTimeout, setInterval, XMLHttpRequest, and Promises, wrapping them in zone contexts. Zone.js enables features like automatic change detection in Angular by providing hooks that trigger when asynchronous operations complete. It's used for performance profiling, error tracking, and debugging asynchronous behavior in web applications. The library is a core dependency of the Angular framework, powering its change detection mechanism. Developers use Zone.js when building applications requiring sophisticated async operation management or custom execution contexts.