What Is JavaScript Used For?

The best websites feature worthwhile information, seamless navigation, and a sharp design that’s pleasing to the eye. While these features may look and feel simple, in reality, it takes a well-educated designer or programmer to develop everything that goes into a website.

In fact, there are three parts that make any website function the way it should: HTML, CSS, and JavaScript. 

Imagine you have a pizza. HTML would be the delicious crust (New York Style, pan-style, whatever you prefer!), since it serves as the foundation of a web page, giving it structure and purpose. CSS would be the sauce and cheese, essential to turning what’s essentially a circle of dough into a scrumptious pizza. CSS builds off the foundation of the HTML element, giving the web page style through colors, fonts, and content placement.

But today, we’ll be focusing on JavaScript—the top toppings of your pizza that turns a simple pizza into an even more delicious and engaging (media) consuming experience. JavaScript gives a web page life and dynamic capabilities, and without JavaScript, websites like YouTube would appear without images, and videos would be unplayable.

So what is JavaScript used for exactly? In order to understand why people learn JavaScript and what it’s used for, first we have to know what it is.

What is JavaScript?

In the most fundamental sense, JavaScript is a computer programming language. It tells a website to present and play the interactive elements to a user. That includes elements like 2D or 3D animations, interactive images like maps, content updates, videos, and more.

The rule for JavaScript is it can make things move. For example, if you’ve ever scrolled through a website displaying videos, animations, forms, or any other non-static information, it’s a safe bet the web page is partially constructed using JavaScript. More specifically, it allows a user to view and interact with specific pieces of content without updating or reloading the entire page.

You may have enjoyed the benefits of JavaScript today without even realizing it:

  • As you scroll through your favorite social media page, videos play automatically—that’s JavaScript.
  • If you rely on a hiking trail navigation website to find new trails using an interactive map, that site uses JavaScript. 
  • And what about your favorite pizza delivery app with a self-updating progress tracker that tells you the status of your pepperoni pizza. Guess what? That’s JavaScript.

Today, JavaScript code is the most popular front-end scripting language, with over 97% of all internet websites utilizing it.
In fact, here are just a few you might know (and love):

  • Netflix  – Netflix is used by more than half of all U.S. households.2 Because of its wide popularity, Netflix was constructed to be easily navigable and customizable. JavaScript code was originally used for front-end development, but since then, its cousin, the Node.js framework, has become the primary programming language. The JavaScript framework is still in use.

  • Candy Crush  – This free-to-play game is one of the most successful apps ever created. With JavaScript’s flexible nature, developers were able to create a mobile device app that looked and felt like Facebook’s app. What’s more, JavaScript enabled Candy Crush to run off Facebook’s native JavaScript framework for easy-linking.

  • Facebook  – Facebook is built off JavaScript’s framework called React Native. This framework was created to solve Facebook’s major problem translating across platforms, such as Apple vs. Android. Now, real-time events and things like surveys load twice as quickly, and Facebook users experience fewer bugs.

  • Uber  – With just the push of a button, users are able to summon a ride to just about anywhere. JavaScript and Node.js are used to process large amounts of data at once, making network requests a breeze. Improvements are made continuously, and the app’s language evolves with its users’ needs.

  • LinkedIn  – LinkedIn is the most widely-used professional networking application in the world, so it’s no wonder that JavaScript is the base framework and programming language. The front and backend developers use JavaScript for quick-processing, improved performance and memory, and a better user experience.

  • All of these applications and so many more are built and developed with JavaScript. The list of technologies and websites using JavaScript continues to grow, and as more people use JavaScript, the experience improves as well.

    What Kind of Programming Language is JavaScript?

    In a technical sense, JavaScript is a front-end language, meaning web developers use JavaScript to make web pages dynamic and visually appealing.

    Another important distinction to make is that JavaScript is considered a “client-side” programming language, which means its scripts are read, interpreted, and executed in the client, or web browser. In contrast, server-side languages run on a remote server (computer) that’s hosting a website.

    Because JavaScript is client-side, developers are able to add interactive features that change and update a web page without any hiccups.

    Why Learn JavaScript?

    Now that you know how prevalent JavaScript is, it’s no wonder front-end developers with skills in this programming language are in such high demand. After all, sleek, stylish websites aren’t just pages full of static information—they’re exciting and dynamic (thanks to JavaScript).

    So why include JavaScript on your list of programming languages to learn? Because you can either expand your skills as a full-stack developer or hone your expertise as a specialized developer.

    Someone who has a full range of programming knowledge in HTML, CSS, and JavaScript is called a full-stack developer. On the other hand, someone who is a master of one particular language is called a specialized developer

    While full-stack developers do come with their own set of pros, specialized developers are prized for their high-quality, specialized skills and how easy it is for businesses to find and hire them. They can take on large, complex projects and still output a quality unseen in full-stack developers.

    Specialized JavaScript developers are particularly in demand, and while there are many reasons to learn JavaScript, the most notable are:

    • It’s the most popular programming language in the world No matter where you are on the globe, you can be sure JavaScript is in use across the world wide web. This makes it easy for programmers to find employment or projects anywhere they are.
    • It’s easy to learn – Because JavaScript fluency is a highly-coveted skill, there are hundreds of classes and online courses dedicated to teaching it. In fact, at Disney Codeillusion, we help students practice the key skills involved in mastering JavaScript, but with an outstandingly-fun curriculum that includes in-depth game and animation development.
    • It’s versatile There are so many different ways to use JavaScript, from creating cross-platform apps to powering smart TVs, making music, and designing art and video games. 
  • It’s the default browser language What is a default browser language? It just means that your browser (whether you use Google, Firefox, or Internet Explorer) has the JavaScript language built-in. You can manipulate and customize a host of things in your browser without setting up editing environments or having to download compilers and learn how to use them. 

  • You can create visual effects, intricate user interactions, and develop games – JavaScript has an extensive library of animations and effects, and you can create your own as well. You can design impressive user interaction experiences, like a fully-interactive resume, and you can even develop games like a simplistic asteroid-shooting game or more advanced, complicated games.

  • JavaScript development is a widely useful skill to hone for all of the above reasons and more. The only real “con” to learning such a versatile language is the amount of time you’d need to dedicate. Yet, the commitment is small in the long run, especially when you consider all the doors you’ll open for yourself—both creatively and in your career.

    Read our guide on, what is the difference between CSS and HTML? to get a better understanding of additional programming languages!

    Careers that Utilize JavaScript

    As of 2021, there are almost 52,000 job listings for JavaScript developers on Glassdoor. Because JavaScript is so versatile, there are a plethora of careers and jobs available such as:

    • Front End Web Developer
    • Web Application Developer
    • Full Stack Web Developer
    • Information Security Software Developer
    • WordPress Developer
    • PHP and JavaScript Developer
    • Freelancer
    • WordPress Speed Optimization Expert
    • Web Developer for IT Cloud
    • Online Commerce Developer
    • Shopify Coder
    • Web Design 
    • Online Repository Developer
    • Java Expert
    • E-commerce Website Developer

    All of these positions make a healthy salary, even at entry-level. For instance, a Front End Developer makes a base salary of about $74,000 on average. This doesn’t include things like bonuses or profit-sharing, which could increase that base salary by a substantial amount.

    Discover the Power (and Fun) of JavaScript with the Magic of Disney

    Because of JavaScript’s broad range of uses and capabilities, it’s easy to see why it’s among the most popular programming languages. Overall, learning JavaScript is a useful and lucrative skill to cultivate.

    Because of how time-consuming and difficult learning to code can be for adults, most online coding courses have an average completion rate of less than 10%.4 However, Disney Codeillusion makes it incredibly fun and rewarding to learn programming. We understand the challenges that come with learning to program; that’s why we set you up for success and an enjoyable learning experience.

    At Disney Codeillusion, we’ll bring the magic and you’ll practice the incredible craft of JavaScript. Start your free trial today!


    1. Mozilla Web Docs. JavaScript. https://developer.mozilla.org/en-US/docs/Web/JavaScript 
    2. W3Techs.com. Usage Statistics of JavaScript as Client-Side Programming Language on Websites. https://w3techs.com/technologies/details/cp-javascript
    3. Glassdoor.com. JavaScript Jobs.https://www.glassdoor.com/Job/javascript-jobs-SRCH_KO0,10_IP3.htm 
    4. Fox Business. Streaming Services by the Numbers. https://www.foxbusiness.com/lifestyle/streaming-services-cost-users
    5. Disney Codeillusion. https://codeillusion.io/pages/coding-for-adults