JavaScript

What is JavaScript ?

JavaScript is a relatively simple scripting language which can be seamlessly integrated with HTML and is used on many websites. JavaScript is less complex and consequently, less powerful than Java.

JavaScript (JS) is a scripting language used to create and control dynamic website content—but that might not make a lot of sense if you’re new to tech. So, let’s replace “dynamic website content” with “things that move, refresh, or otherwise change on your screen without requiring you to manually reload a web page.”

Think features like animated graphics, photo slideshows, autocomplete text suggestions, and interactive forms. Or even better, think about web features you completely take for granted, like when your Facebook timeline updates on your screen or Google suggests search terms based on a few letters you’ve typed into your search bar. In both cases, that’s JS in action.

Basics of JS

You can see from the examples above that—if you’re interested in web development—the answer is a resounding yes. So, with that out of the way, let’s go a bit deeper into how JavaScript works and what you’ll really use it for.

I mentioned above that JavaScript is a “scripting language.” Scripting languages are coding languages used to automate processes that users would otherwise need to execute on their own, step-by-step. Short of scripting, any changes on web pages you visit would require either manually reloading the page, or navigating a series of static menus to get to the content you’re after

A scripting language like JavaScript (JS, for those in the know) does the heavy lifting by telling computer programs like websites or web applications to “do something.” In the case of JS, this means telling those dynamic features described earlier to do whatever it is they do—like telling images to animate themselves, photos to cycle through a slideshow, or autocomplete suggestions to respond to prompts. It’s the “script” in JavaScript that makes these things happen seemingly on their own.
JS comes built into your web browser

Because JavaScript is such an integral part of web functionality, all major web browsers come with built-in engines that can render JavaScript. This means JS commands can be typed directly into an HTML document, and web browsers will be able to understand them. In other words, using JavaScript doesn’t require downloading any additional programs or compilers.