What is JavaScript? What is JavaScript Used For?

The software development world is very wide and complex. Seemingly every company has a website, mobile application, or social media account. While the latter does not require much programming, the point still stands - everything is going digital. Of course, with an increase in demand, there appears to be a shortage of professional software developers. If you are up to the task of becoming a programmer, there might be a small issue - there are just so many different languages you could use to write software, that many beginners do not know where to start. Today, we hope to help you get a more in-depth look at JavaScript, a very popular and versatile programming language. Read on to find out what is JavaScript and what JavaScript is used for.

Updated: 03 Apr, 22 by Antoniy Yushkevych 12 Min

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JavaScript, you might have heard about it before, is one of the most popular computer programming languages. Most of the time, developers use JavaScript to build website applications. JavaScript is used in images, forms, carousels, etc., on a website. JavaScript is backed by the Node.js framework that takes care of the website's other features, such as the processing of the images and forms, payment features, and so on. 

However, JavaScript language needs a clear understanding to be executed by beginners. Before you learn how to code in the JavaScript language, there are a few things you need to know about JavaScript. So, in this post, we will help you understand the basics of JavaScript and what JavaScript is used for.


Whenever you open a website on a browser, you are likely to see a web page that shows static content and a lot more than that. You will find advertisements, product sections, forms, and other things, along with the static content. JavaScript helps those things show on a webpage. This also means that the webpage is running JavaScript in the background. JavaScript is a programming language that is human-readable because it is based on text. JavaScript is used in client-side and server-side development to create an interactive webpage, while HTML and CSS languages form the proper structure of the webpage. Along with HTML and CSS, JavaScript makes the webpage visual with various elements such as graphics, information, and so on to engage the visitors. 

For example, JavaScript is used on your Twitter feed. Every time you refresh it, it will show you the Tweets you haven't read already. Another example of a JavaScript-based platform is the Amazon search box and the videos that are embedded on online news sites such as NDTV.com. Therefore, the primary motive of JavaScript is to take the webpage from a static state to a more interactive one.

There are several cases where developers prefer to use JavaScript to other languages. Let's find out those scenarios. 


JavaScript is a lightweight text-based programming language that allows dynamic interactivity on your website when you compile it with the HTML document. Developers can use JavaScript to create modern applications that interact among themselves without refreshing the webpage every time. There are four main uses of JavaScript that determine the behavioral pattern of your webpage. Let's get to know them first.

Making the Web Page Interactive

JavaScript allows developers to add interactive features to their web pages so that users find the site more engaging and pleasurable to visit. These features may include changing the text size & appearance, image size & appearance, etc., on their own so that the users find it more attractive. There are no restrictions to the features that you can add using JavaScript, and here are some examples:

  • Show or hide information when a user clicks on a button.
  • Zoom in or out an image on your webpage when a mouse pointer hovers over it.
  • Using a drop-down menu.
  • Displaying videos or audio on your webpage.
  • Displaying various animations.
  • Showing a series of tabs or menus on a webpage.
  • Showing image slides on your website.
  • Changing the color of text when the user selects it.

There can be many other ways you can make your website interactive. These are just a few examples. But making your website attractive is not the only purpose of JavaScript. 

Creating Web Applications and Mobile Applications

Developers use various JavaScript scripts to build web applications and mobile applications all the time. There are several JavaScript code libraries in the JavaScript framework where developers can access pre-written codes to use for programming features and tasks. These codes help you build websites and web applications. JavaScript is used in many popular applications such as Netflix, PayPal, LinkedIn, etc.

Developing Server Applications

Apart from websites and web applications, developers use JavaScript to create web servers. They develop the back-end structure using Node.js. Node.js is a tool in JavaScript that supports programming for the server-side infrastructure. Back-end code helps a webpage work on the server, and Node.js utilizes JavaScript to save data from the server to a database. With the JavaScript back-end, a website can prepare its payment system, save the user posts, and conduct other essential business functions that keep a site running smoothly.

Game Development

Since JavaScript developers can develop web applications, mobile applications, web servers, and website pages, it is also helpful in creating cross-platform video games. More specifically, JavaScript is practical in the creation of browser games. However, creating video games using JavaScript is more straightforward than using the language for the three uses mentioned above. That's why beginner developers use JavaScript to create web-based games in order to practice their JavaScript skills. 

These are the primary uses of JavaScript, but since there are other programming languages out there, so why do you need to use JavaScript anyway? 


Even when compared to others, JS is superior to other programming languages because it provides you with a number of benefits. It allows you to creatively show your content on your web pages and add various visuals to make it more interactive. Nevertheless, there are other vital reasons why developers use JavaScript over other programming languages:

  • JavaScript works on all web browsers, and it is the only programming language of its kind.
  • It is the most trusted and secure programming language.
  • JavaScript is straightforward to learn.
  • It does not take much time or cost to get started with JavaScript.

There are already some famous web applications that are based on the JavaScript programming language. 


PayPal has been built on JavaScript since the very beginning; it also uses Node.JS to make it suitable for all types of web browsers. PayPal has even created its own Express JavaScript framework for PayPal web interfaces.


Netflix is another popular platform that uses the Node.Js framework. It works on all platforms and web browsers alike.


Both Facebook and Instagram use JavaScript, and these platforms are immensely popular and interactive.

These are the famous websites that use JavaScript for their web pages. And these companies have their reasons — as described above, to choose JavaScript. However, if you also wish to learn JavaScript, you should know why it is a good idea.


There are so many options to choose from when you are learning a programming language. You can choose to study Python, Java, JavaScript, PHP, and more. But since there are so many programming languages, why would you choose JavaScript particularly? Here are some significant reasons why learning JavaScript can be the best for your software development career.

JavaScript is Immensely Popular

Front-end and back-end developers often choose JavaScript to develop websites and various web applications. Even though there are many alternatives to JavaScript, choosing JavaScript helps you add more features to your project, and it is easy to use. That's why JavaScript is becoming more popular with each passing day.

It Has Career Potential

Nowadays, people mostly do business online, which is why individuals look for developers who know JavaScript. In fact, companies and individuals pay a high salary to developers who are familiar with JS. The average pay of a professional JS developer is $113,643 in the USA. And as of 2021, there are 364,000 new job openings for JavaScript developers.

JavaScript is Versatile

With JavaScript, you can manage every part of an application's design. You can make desktop, mobile, web applications, and so on with JS. JavaScript should be your ultimate choice even if you are interested in user-side or server-side coding and machine learning mechanisms.

JavaScript Helps You Keep Users Engaged 

With so many graphics and visual elements, it's easy to keep your visitors entertained on your site or application. You can add interactive maps, videos, animations, all simultaneously without losing the performance of your project.

These are the most important benefits of learning JavaScript for your career. But how do these advantages make JavaScript different from other programming languages?


In earlier days, people only used programming languages for web development for the internet. However, the requirements have shifted focus throughout the decades to mobile, web, and desktop application development at a more complex level. These days, JS is more flexible and easy to use than Python and Java. In Python, the data processing is more complex than in JavaScript. JavaScript has data libraries where you can manipulate the HTML in the internet browser. Also, Python only responds to function calls, while JavaScript only requires a few mouse clicks to perform most functions. 

Hence, JavaScript has mode advantages over Python, but if you compare JavaScript to another popular programming language in an apples-to-apples comparison, it would be Java. Java is a network-based programming language, but JavaScript is a scripting language. With Java, you can only monitor and control the network, but JavaScript is more versatile. You can use it for almost everything that we have talked about. And another significant difference between Java and JavaScript is, Java is static while JavaScript is dynamic.

JavaScript has become more flexible because it has gone through numerous developments that have improved the programming language. The continuous growth of JS has made it more likable to developers. However, before you make up your mind about using JavaScript for your software development projects, you need to consider its various advantages and disadvantages.


JS definitely has advantages over Java, Python, and other popular programming languages. However, there are many advantages and disadvantages it comes within itself. Let's find them out.


  • JavaScript is fast on the client-side or front-end side because you can run it within the browser without additional resources. If other resources are involved, the speed may be compromised. 
  • JavaScript is easier to learn and implement than other programming languages.
  • JavaScript is used everywhere online.
  • You can use JavaScript in different kinds of applications.
  • It reduces the demand for the website server because it runs on the client-side directly.
  • You can create attractive interfaces with JS.


  • The security of the client-side can be compromised since the code is generated on the users' computers.
  • Many different browsers support JavaScript, but sometimes you have to write cross-browser codes because the same code might not be suitable for a different browser.


Everything has its advantages and disadvantages, and so does JavaScript. However, you can eliminate the security downfalls of JavaScript by taking extra precautions while using JS on your website. For example, secure your site with a robust privacy and security plugin.

JavaScript has been used to create a seemingly endless number of front-end and back-end applications over the years. Moreover, not only by Facebook and Netflix utilize JavaScript. It is also used in many popular platforms, including Uber and Walmart. So, if you are wondering whether or not learning JavaScript will be helpful for you, don't think twice.

Antoniy Yushkevych

Antoniy Yushkevych

Master of word when it comes to technology, internet and privacy. I'm also your usual guy that always aims for the best result and takes a skateboard to work. If you need me, you will find me at the office's Counter-Strike championships on Fridays or at a.yushkevych@monovm.com