Web Workers are a way to run JavaScript code in the background, without blocking the main thread. This is useful for running heavy tasks, such as image processing or data analysis, without slowing down the user interface.

Web Workers are separate threads of execution that can communicate with the main thread using message passing. This means that you can send data to a Web Worker, have it perform some computation, and then send the results back to the main thread. This allows you to keep the user interface responsive while performing heavy tasks in the background.

Here's an example of using a Web Worker to perform a heavy computation:

// Create a new Web Worker
const worker = new Worker('worker.js');

// Send data to the worker
worker.postMessage({ data: [1, 2, 3, 4, 5] });

// Listen for messages from the worker
worker.onmessage = (event) => {
  // Handle the results
  console.log(event.data);
};

// worker.js
// Listen for messages from the main thread
self.onmessage = (event) => {
  // Perform some computation
  const result = event.data.reduce((acc, val) => acc + val, 0);

  // Send the results back to the main thread
  self.postMessage(result);
};

In this example, we create a new Web Worker and send it an array of data. The Web Worker performs a computation on the data and sends the result back to the main thread. The main thread listens for messages from the Web Worker and handles the results.