Industry Usecase of JAVASCRIPT

What is JavaScript?

JavaScript is a programming language used primarily by Web browsers to create a dynamic and interactive experience for the user. Most of the functions and applications that make the Internet indispensable to modern life are coded in some form of JavaScript.

The earliest incarnations of JavaScript were developed in the late 1990s for the Netscape Navigator Web browser. At the time, Web pages were static, offering little user interaction beyond clicking links and oading new pages. For the first time, JavaScript enabled animation, adaptive content and form validation on the page.

For many years, JavaScript only functioned on a limited number of browsers. Microsoft’s Internet Explorer, the largest browser base, did not support JavaScript until much later. Instead, Microsoft created its own proprietary client-side script called JScript. In the early days of Web development programmers who wished to create dynamic websites were often forced to choose one browser family over the other. This was less than ideal because it made the Internet less universally accessible.

JavaScript did not become standardized and widely adopted until 1999. Even after standardization, browser compatibility remained an issue for over a decade.

How does JavaScipt work?

JavaScript is what is known as a client-side script. Most Web applications, , work because of an interaction between the user’s device (e.g. computer, ) and a remote server. The software on the remote server sends information to the client (i.e. the user’s machine) and the software on the client side reads the information and renders a Web page on screen.

A client-side script is a programming language that performs its tasks entirely on the client’s machine and does not need to interact with the server to function. For instance, if you have a Web page loaded on your computer and your Internet service provider goes down, you are still able to interact with the Web pages already loaded on your browser. You will not, however, be able to navigate to new Web pages or access any data located remotely.

Some of the dynamic website enhancements performed by JavaScript are:

  • Autocomplete
  • Loading new content or data onto the page without reloading the page
  • Rollover effects and dropdown menus
  • Animating page elements such as fading, resizing or relocating
  • Playing
  • Validating input from Web forms
  • Repairing browser compatibility issues

While JavaScript is a client-side language, some of its most powerful features involve asynchronous interaction with a remote server. Asynchronous simply means that JavaScript is able to communicate with the server in the background without interrupting the user interaction taking place in the foreground.

Take a search engine for example. Today, search engines almost all have an autocomplete function. The user begins typing a word into the search box and a list of possible search terms or phrases appears below. The experience is seamless. Suggested search terms appear without reloading the page.

In the background, JavaScript reads the letters as the user types, sends those letters to a remote server and the server sends suggestions back.

The software on the server side analyzes the words and runs algorithms to anticipate the user’s search term. Such programs are diabolically large and complex. The JavaScript on the client’s machine is as simple and small as possible so as not to slow down the user’s interaction. The communication between JavaScript and the server-side program is limited by the user’s bandwidth. This is why developers prioritize efficiency in JavaScript functions and make the amount of data communicated between the programs as small as possible.

Only once the user selects a search term does the entire page reload and produce the search results. Engines such as Google have reduced or eliminated the need to reload, even for that step. They simply produce results using the same asynchronous process.

The future of JavaScript

While JavaScript is not the only client-side scripting language on the Internet, it was one of the first and it is still the most widely used. Many developers believe that JavaScript is inefficient and finicky, so they have made many improvements to the language over the years. Enterprising programmers have created JavaScript libraries — more concise languages constructed from the building blocks of JavaScript that are less complex and can be targeted for specific applications.

Industry usecase of JavaScript:


Okay, so you’re probably not going to find JavaScript powering Windows anytime soon, but Microsoft relies on JavaScript for a whole lot else. First off, Microsoft needs to work closely with JavaScript to built its Edge web browser. All browsers need to process and execute JavaScript efficiently, so Microsoft has developed and maintains its own JavaScript engine for Edge. Actually, there has been talk of them creating an alternate version of NodeJS with the Edge engine. Recently, Microsoft has really embraced NodeJS. They thoroughly support Node on the Azure cloud platform. Its one of Azure’s major features, and they’ve integrated Visual Studio support for Node. Microsoft has also developed a version of Node for Internet Of Things(IoT) applications. NodeJS is great of IoT because it’s light weight and efficient.


PayPal has obviously been using JavaScript on the front end of their website for a long time, but that’s only the beginning. The online payment giant was one of the earliest adopters of NodeJS. During an overhaul of their account overview page, they decided to try building the page in Node at the same time as their usual Java development. The NodeJS version worked out so well, that they chose to use it in production and build all client-facing applications in Node going forward. That means that most of what you see in your account is running on Node. PayPal even went as far as to create and maintain their own version of Express, called . It’s pretty obvious that they like JavaScript over at PayPal.


Like PayPal, Netflix started out using Java for just about everything. They too ran into problems with Java’s size and the time it required to develop.

Over time, Netflix moved away from its more traditional structure into the cloud and started to introduce NodeJS. With Node, Netflix was able to break down pieces of their user interface into individual services. This more distributed approach was able to speed things up an alleviate stress on their servers. Today, a large portion of Netflix’s interface is running on Node.


How doesn’t Google use JavaScript? Seriously, it’s everywhere. Google’s search results that spring up as your typing get there with JavaScript. The Gmail web client is powered by JavaScript. Google Docs? Yeah, that’s JavaScript too. Google develops and usually open sources it’s own JavaScript tools. The most obvious example is AngularJS. Angular is used most prominently in Google’s DoubleClick advertising platform, but it’s also one of the most popular front end frameworks available. It’s even part of the MEAN stack. Google’s more intensive services, like Google Docs, use Closure Tools. This set of tools compiles JavaScript into a lower-level faster form more suited for rich and highly responsive web applications. There’s another big point to touch on. Google developed Chrome. Chrome, being a web browser, needed a JavaScript engine, so Google also made V8. V8 not only powers Chrome, it’s at the heart of NodeJS. So, without Google, there would be no Node.

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