Web Workers – Background Threading

Web Workers run in a separate thread with no direct DOM access.

// worker.js
self.addEventListener('message', e => {
  const result = heavyCalc(e.data);
  self.postMessage(result);
});

Main thread:

const worker = new Worker('worker.js');
worker.postMessage(42);
worker.onmessage = e => console.log('Result:', e.data);