Java Vs Javascript – Why is Java script called Javascript?

Programmers, developers and internet users have always been confused between Java and JavaScript. Many people still think that JavaScript is part of Java platform, which is not true. In truth, JavaScript has nothing to do with Java, the only common thing between them is word “Java”, much like in Car and Carpet, or Grape and Grapefruit. JavaScript is a client-side scripting language for HTML, developed by Netscape, Inc, while Java is a programming language, developed by Sun Microsystems.

What is Java?

Java is a general-purpose programming language designed with one mantra in mind—”write once, run anywhere.” Java applications are compiled into bytecode that can run on implementations of the Java Virtual Machine (JVM). JVM helps bridge the gap between source code and the 1s and 0s that the computer understands. Any machine that has the JVM installed can run Java. In web development, Java features most prominently as a server-side language and the programming language of choice for mobile apps on the Android platform. It also still has a decent presence on the front-end as a Java applet, although this is falling out of favor due to security concerns.

What is JavaScript?

Alongside HTML and CSSJavaScript (standardized as ECMAScript) is considered one of the big three core components of the web. Employed by a majority of websites, JavaScript is a scripting language that typically runs in the browser and makes web pages dynamic and interactive. Today JavaScript is also quickly growing as a server-side technology since the release of Node.js in 2009.




Let’s take a look at some of their similarities and differences between Java and JavaScript:

Both Can Run in a Browser

JavaScript runs on most modern browsers, and most websites take advantage of this to enhance the user’s experience. Java applets can also run in a browser, but they have been declining in popularity for various reasons, including compatibility and security. It is reasonable to expect a website visitor to have JavaScript enabled and it is common for a website visitor to have Java applets disabled, especially with the proliferation of mobile browsers.

Both Can Run on a Server

Java has long been a major workhorse of the web with application servers like WebSphere, JBoss, and Apache Tomcat running a large portion of the web applications seen by users on both public sites and behind corporate firewalls. While JavaScript has dabbled in the server-side realm for a while, the recent popularity of Node.js is causing more JavaScript-powered application servers to pop up all over the place.

Compiled vs. Interpreted

Java code is typically written in an Integrated Development Environment (IDE) and compiled into bytecode. This bytecode is not readable by humans and any Java Virtual Machine (JVM) should be able to run it. JavaScript code is normally executed by a JavaScript engine in the same syntax in which it is written, although JavaScript files that are sent over the internet are often compressed into a barely readable format to reduce their size. Making changes in Java application environments can require several steps using specialized software to compile and deploy the changes while making changes to JavaScript can sometimes be done with just a simple text editor.

Two-Stage vs. Runtime-only Debugging

Java is compiled before it can be run, so if there are any structural problems with the code they become apparent very quickly. Once it is running, IDEs often enable the developer to attach to the JVM to debug in real-time. JavaScript is not compiled in the same way, so all bugs are found at runtime. As such, the debugging capabilities of JavaScript are highly dependent on the execution environment and this can vary quite a bit.

Both Have Libraries and Frameworks

Libraries and frameworks help programmers by providing access to general and purpose-specific code that can be reused over and over again for different products. When used properly, libraries and frameworks can cut development time – sometimes by a very significant factor. Both Java and JavaScript are mature enough to have a wide range of library and framework options available to assist developers in a variety of scenarios.

Static Vs Dynamic Type Checking

Java uses static type checking, where the type of a variable is checked at compile-time. The programmer must specify the type (integer, double, string, etc.) of any variable they create. JavaScript, like most scripting languages, uses dynamic typing, where type safety is verified at runtime. It is not required for a programmer to specify the type of any variable they create. There are many pros and cons for these two paradigms, but the primary advantage of static type checking is that type errors are caught early in development, and because the compiler knows exactly what data types are being used, code typically executes faster or uses less memory. The primary advantage of dynamic type checking is programmer productivity—you are free to assign types at your leisure.


The ability to handle the execution of several instruction sequences at the same time is handled very differently between Java and JavaScript. Java makes use of multiple threads to perform tasks in parallel. JavaScript, particularly as it exists as Node.js in server-side applications, handles concurrency on one main thread of execution via a queue system called the event loop, and a forking system called Node Clustering. For most use-cases, both methods work just fine, but Java is generally faster because thread to thread memory sharing much faster than interprocess communication (IPC).

Class-Based Vs Prototype Based

Java follows class-based inheritance—a top-down, hierarchical, class-based relationship whereby properties are defined in a class and inherited by an instance of that class (one of its members). In JavaScript, inheritance is prototypal—all objects can inherit directly from other objects. Hierarchy is accomplished in JavaScript by assigning an object as a prototype with a constructor function.

Should I use Javascript or Java for my next Project?

As with all languages, the choice really boils down to what you’re trying to build and what resources you have at your disposal. JavaScript is still very much a web technology, whereas Java is a general purpose language that can build anything.

You should consider Java if your project involves…

  • Android Apps
  • Enterprise Software
  • Scientific Computing
  • Big Data Analytics
  • General Purpose Programming of Hardware
  • Server-Side Technologies like Apache, JBoss, Geronimo, GlassFish, etc.

You should consider JavaScript if your project involves…

  • Dynamic single page applications (SPAs)
  • Front-End technologies like jQuery, AngularJS, Backbone.js, Ember.js, ReactJS etc.
  • Server-Side technologies like Node.js, MongoDB, Express.js, etc.
  • Mobile App Development through PhoneGap, React Native, etc.

Why is JavaScript called JavaScript?

JavaScript was originally named Mocha, later it was renamed to LiveScript, and then to JavaScript. The LiveScript to JavaScript name change came because Netscape and Sun did a license agreement.

The language was then submitted for standardization to the ECMA International Organization. By that time, Netscape didn’t allow the use of the “JavaScript” name, so the standardized language is named ECMAScript. JavaScript isn’t actually an open name. Now it’s a trademark of Sun (now Oracle).

There still a lot of confusion, some people still think that JavaScript, JScript, and ECMAScript are three different languages. ECMAScript is the “standards” name for the language. JavaScript is technically a “dialect” of ECMAScript, the Mozilla Foundation can use “JavaScript” as the name of their implementations (currently present on the Rhino and SpiderMonkey engines).