JAVA Script is a scripting language used to create and control dynamic website content, i.e. anything that moves, refreshes, or otherwise changes on your screen without requiring you to manually reload a web page. An even better way of understanding what JavaScript does is to think about certain web features you use every day and likely take for granted—like when your Facebook timeline automatically updates on your screen or Google suggests search terms based on a few letters you’ve started typing. In both cases, that’s JavaScript in action. Many developers and businesses have used JavaScript to extend their web products outside of the browser, which means JavaScript can be used build simple desktop and mobile apps.