Explanation/Reference:
Note:
* Despite the improvements in JavaScript engines, it is not uncommon for users to encounter frozen user interfaces as the browser works through resource intensive tasks. This leads to a horrible user experience.
The purpose of Web Workers is to give developers a way of instructing the browser to process large tasks in the background; therefore preventing the UI from freezing up.
* The Web Workers specification defines an API for spawning background scripts in your web application.
Web Workers allow you to do things like fire up long-running scripts to handle computationally intensive tasks, but without blocking the UI or other scripts to handle user interactions