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Java vs JavaScript: What's the difference?

Sep 30, 2021 - 5 min read
Erin Schaffer

Java and JavaScript are two popular programming languages within software development. While the two languages have similar names, they’re very different from each other. In this article, we’ll take a closer look at each of these languages, explore their similarities and differences, and discuss which one you should use for your projects.

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Java for Programmers

What is Java?

Java is a general-purpose, class-based, object-oriented programming language. We can also use it as a computing platform. It’s a very popular language in application development. Java is used for a variety of things, such as:

  • Front-end development
  • Back-end development
  • Android apps
  • OOP apps
  • Mobile apps
  • Scientific computing apps
  • Big data analytics
  • Hardware devices
  • Server-side development technologies like JBoss, Apache, and more

Let’s take a look at some of the pros and cons of Java:


  • Fast
  • Secure
  • Reliable
  • Platform-independent
  • Automatic memory management
  • Multithreading capabilities
  • Great for distributed computing


  • Memory consumption
  • Verbose
  • Slower compared to natively-compiled languages like C or C++

Java Platform is a collection of Java programmers that help us develop Java code and run Java applications. It was developed by James Gosling at Sun Microsystems, and it was later acquired by Oracle. The Java Platform has an execution engine, a compiler, and various libraries. There are three major components of the Java platform: Java Development Kit (JDK), Java Virtual Machine (JVM), and Java Runtime Environment (JRE).

Java Development Kit (JDK)

JDK is a development environment that we can use to make Java applets and applications. We can use it on Windows, Linux, macOS, and Solaris. JDK has the tools we need to write programs, and it converts code written in Java into bytecode.

Java Virtual Machine (JVM)

JVM provides a runtime environment for our code. It’s part of the Java Runtime Environment. JVM gives us a way to execute our Java code in a platform-independent way. It comes with a JIT compiler that converts our source code into low-level code to help it run faster.

Java Runtime Environment (JRE)

JRE contains class libraries, loader classes, and JVM, and it’s the tool we use to run our Java programs. It uses package classes and runtime libraries to help us execute our programs.

What is JavaScript?

JavaScript is a client-side, cross-platform, object-oriented scripting language created by Brandon Eich. JavaScript is widely used in web development, and it’s a great language to use to help build dynamic and interactive web pages. JavaScript has many applications, including:

  • Game development
  • Mobile app development
  • Web app development
  • Building web servers and server applications
  • Adding interactivity to web pages

JavaScript runs directly in the web browser, which means we don’t need any additional resources to execute our JavaScript code. It can also run on a server via Node.js. We can use JavaScript to insert dynamic text into HTML. It has a relatively relaxed syntax.

Let’s take a look at some of the pros and cons of JavaScript:


  • Fast
  • Simple
  • Popular
  • Interoperable
  • Versatile
  • Rich libraries


  • Security
  • Browser support
  • Debugging
  • Single inheritance


Overall, Java and JavaScript don’t have many similarities. They’re both object-oriented programming languages, and they’re both used in web development. Java and JavaScript can run on servers or in a browser, and they both have various libraries and frameworks to help us execute our programs efficiently and effectively. The two languages have a lot more differences than they do similarities. Let’s take a look at the major differences between these two popular programming languages.

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Java for Programmers

Key differences

Let’s take a look at some of the main differences between Java and JavaScript:


  • Compiled
  • Mainly used for back-end development
  • Static type checking
  • Compiling language
  • Executed in JVM
  • Works on class-based objects
  • Use JDK to write programs
  • More secure
  • Provides multithreading
  • Standalone


  • Interpreted
  • Mainly used for front-end development
  • Dynamic type checking
  • Scripting language
  • Executed in the browser
  • Works on prototype-based objects
  • Use a text editor
  • Less secure
  • Doesn’t support multithreading
  • Placed inside HTML

Wrapping up and next steps

So, which one should I learn?

Java and JavaScript both have their own advantages and disadvantages. It really depends on the work you’re doing and what you hope to accomplish. You should consider Java if you’re working with Android apps, scientific computing, big data analytics, or general-purpose programming. You should consider JavaScript if you’re working with dynamic web page applications, front-end technologies, or mobile app development. Overall, it’s important to take your project or work into consideration and do your research to ensure you’re using the right language.

We covered a lot today, but there’s still so much more to learn about both of these object-oriented languages. If you want to start getting hands-on with Java or JavaScript, check out Educative’s courses and learning paths to start your journey. Our Java for Programmers learning path is a perfect introduction to the Java programming language. Our Become a Front End Developer learning path is ideal for you if you’re looking to get hands-on with JavaScript, HTML, and CSS to create functional websites and web applications.

No matter which learning path you choose, you’ll learn valuable skills that will help you take your programming to the next level.

Happy learning!

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WRITTEN BYErin Schaffer

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