What do we need?
In JavaScript we don’t need to necessarily install literally anything, reason being; since JavaScript is mostly used for scripting for the web we can literally just start programming in the browser. This is because Chrome for example, literally is running their scripts using V8 JavaScript engine which is native to the browser. (You might also know that Node.js is a runtime built on V8). Similarly, other browsers uses a runtime of its own like Firefox(SpiderMonkey), Opera(JavaScriptCore(JSC)/Nitro), and Edge(Chakra-> which got rebuilt using Chromium and v8)
Summary: No you don’t need to install anything at the moment.
Server-side development
As we all know, JavaScript is mostly associated with web applications and web development together with it’s complementary parts HTML and CSS. But what happens if you want to develop applications on your machine using JavaScript as your backend? That’s where other languages like Python and Java comes in but with something like a runtime environment (able to run your code) NodeJS will also allow you to use JavaScript as your backend as well.