JavaScript (not to be confused with Java) is a flexible language that can be used for both the front-end and back-end. It is a good language for beginners because it has little customization and you can start writing code right in your browser.
The flexibility of JavaScript can be expensive at times: scripts are slow, difficult to maintain, and difficult to scale, as in most dynamically typed languages.
JavaScript has a large community, and there are many useful materials to learn about it on the web.
The Node.js software platform significantly expands the capabilities of JS. With its help, code written in JS can be run without a browser on the backend. And the presence of a huge number of ready-made solutions in the npm package ecosystem allows the developer not to waste time creating most typical solutions.
What you can do in JavaScript
With JavaScript, web applications and software are created, namely:
front-end and back-end websites;
mobile applications;
desktop applications;
games;
web servers;
presentations;
and much more.
Which companies use JavaScript
Airbnb, Codecademy, HotelTonight, eBay, Square, Asana.