Worker

A Worker is a separate execution context used to run tasks in the background without blocking the main thread. It executes code independently, communicates with the main context via message passing (for example, postMessage and onmessage), and can transfer large data efficiently through transferable objects. Workers are ideal for CPU-intensive operations, such as data processing or image manipulation, to keep user interfaces responsive. They come in different forms across environments (Web Workers in browsers and Worker Threads in Node.js) and generally lack access to the DOM or the global window object, requiring explicit communication and careful error handling.