What is Java Used for? [All You Need To Know]

Velina Nenova
Velina Nenova

Updated · Oct 16, 2022


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If you had a computer with an internet connection in the mid to late 90s, you most likely recall the “hot cup of coffee” logo loading in your browser.

The logo also refers to the island of Java, which is synonymous with coffee.  

But what does it mean and what is Java used for?

Aside from helping many of us start our days, coffee seems to have been the fuel behind the Sun Microsystems engineers’ efforts when developing Javascript.

First launched in 1995, it rose to be a primary programming language.  

It’s the backbone of millions of applications ranging from web and mobile apps to server setups, embedded systems, and big data technologies.

The uses of Java are numerous, as you’ll discover in this article. 

Lets first briefly look at what Java is.

What Is Java?

As a technology, Java consists of a programming language and a software platform. 

Its portability capabilities can overcome implementation dependencies as much as possible. As such, programmers can write code on Windows and then implement it on a mobile phone without revisions. For this reason, Java was released under the fitting slogan “write once, run anywhere” (WORA). 

And while this is a popular characteristic, it’s far from being Java’s only distinct trait.

It’s important to note that JavaScript is not the same as Java. The main differences are that the former is a language type that runs only on browsers and needs no compiling. On the other hand, the latter is an OOP language that can run anywhere and needs compiling. 

With that out of the way, let’s proceed.

Java Language

Java is an object-oriented programming (OOP) language that is class-based. This means that its code represents classifiable real-world objects. Other languages use functions and commands instead. 

It’s also considered a high-level language.

In computer science, this refers to scripts close to human ones, as opposed to low-level languages. These are also known as machine level and are understood by computers, for example, binary code. 

Java code, meanwhile, resembles abbreviated English sentences.

This makes learning, reading, understanding, and writing it much more manageable.

Java Platform

The Java software platform is a bundle of components that allow programs to be written in Java.

There are four primary platforms:

  • Java Platform Standard Edition - Java SE
  • Java Platform Enterprise Edition - Java EE
  • Java Platform Micro Edition - Java ME
  • Java FX

Java SE primarily creates standalone programs, while Java EE is more for businesses, industries, and network applications. 

Java ME leans towards mobile devices, and Java FX is a set of graphics and media packages aimed at rich internet applications and multi-platform consistency.

Depending on your Java usage needs or requirements, you need to install one of these platforms to start programming. These are better known as Java Development Kits (JDKs), and they all include the following components:

  • Compiler - This is a predefined program that evaluates user-written code and translates it to machine-level bytecode that the computer recognizes.
  • Java Virtual Machine (JVM) - when installed, it processes the code into a user-readable format. And as long as it compiles into bytecode, you to run anything written in Java or other programming languages
  • Application Programming Interface (API) - Java APIs are software components that, among other things, include classes, interfaces, and user interfaces. These allow communication between an app under development and one or more already developed ones.

The other file that comes with the platform is Java Runtime Environment (JRE). This is the implementation of the JVM and provides an environment to run Java applications. It doesn’t contain any development tools but consists of JVM, Java binaries, and other classes. 

If you only want to execute Java programs, you only need JRE.

In addition to the above, numerous Integrated Development Environments (IDEs) provide tools and libraries to support programming Java applications for different uses, like education, mobile apps, gaming, etc. The most popular ones are:

  • Eclipse
  • BlueJ
  • IntelliJ IDEA
  • Netbeans
  • JDeveloper

Some of these, like IntelliJ IDEA, support other languages like Scala and Kotlin, or Netbeans, which supports C, C+, PHP, and more.

So how does it all work?

To create an application with Java, you need first to download a JDK or an IDE that includes the former. Secondly, write the code using the Java language and use the compiler in the development kit to turn the code into bytecode - the instruction set for the JVM. Once completed, the compiled bytecode can run on any system without modifications.

With this basic understanding of how Java is used, let's now look at why this technology is still so popular.

What Is Java Used For?

Java has been around for about 27 years, which is a long time in “technology years.” 

It is regularly in the top three most used programming languages. Currently, it holds third place according to the TIOBE index

According to Oracle, which acquired Java and Sun Microsystems in 2010, around three billion devices have some form of Java in their programming.

If this seems surprising, just look at the list of applications below, and you’ll understand why the use of Java is so widespread.

Mobile Applications

The Java ME platform is used in apps across all mobile devices to a certain extent. The language, however, is most widely used as the base for Android. It accounts for around 46% of this OS’s applications and is often considered the official Android language. Some notable apps using Java are:

  • Netflix
  • Google Earth
  • Uber
  • Spotify 

Desktop GUI Applications

Java provides many features that help develop Graphic User Interfaces (GUIs). Libraries like the Abstract Window Toolkit (AWT), Swing API, and Java FX provide features like pre-built buttons or menus. It also allows programmers to develop advanced tree-based or even 3D GUI applications. Popular apps developed with Java include:

  • Adobe Reader
  • ThinkFree

Web Development

Java became a prominent web development language due to its now obsolete browser applets - one of the most famous examples of Java web applications. Programmers nowadays utilize technologies like Struts, Servlets, Spring, etc. Thanks to these, Java continues to be a prevalent option for back-end server-run web apps, like:

  • Spotify
  • Amazon
  • Netflix

Game Development

Although game engines like Unity and Unreal use coding scripts like C++ and C#, Java is still great if you want to learn game graphics and development from the ground up. This is largely thanks to its powerful JMonkeyEngine. Some notable games written in Java are:

  • Contra
  • The Sims 3
  • Minecraft

Web and Application Servers

The Java ecosystem is widely used in both web and app server software.
Web server software includes:

  • Apache Tomcat
  • Project Jigsaw
  • Jetty

Notable application servers are:

  • IBM’s WebSphere

  • Wildfly

  • Apache Geronimo

Internet of Things

Cross-platform adaptability and portability are what define Java. That’s why programmers often regard it as the best choice for IoT device development. It substantially reduces workload - since you can write the code once and run it on numerous devices without much hassle. Some uses are:

  • Smart wearables

  • Smart TVs

  • Auto-navigation systems

Scientific Applications

Thanks to its security, speed, and highly-portable environment, Java is excellent at handling scientific or mathematical computation, analysis, visualizations, etc. Notable scientific uses include:

  • NASA’s WorldWind
  • JavaFX Deep Space Trajectory Explorer
  • BioJava

Embedded Systems

The initial purpose of Java was for the implementation in embedded systems. These are a combination of several smaller systems that work in conjunction. This includes processors, chips, and microcontrollers, to name a few. It supports the following: 

  • SIM Cards
  • Blu-ray discs


These applications are large software systems that run at a corporate level. Development of intranets and large-scale, multi-thread internal software systems are some of the primary uses of Java. Its Enterprise Edition provides capabilities for scripting tasks, network applications, and web services, to name a few. According to Oracle Corporation, Java runs on around 97% of enterprise-owned computers, including:

  • Google
  • Infosys
  • Wipro

Financial Industry

Financial institutions like banks require multiple programs for data processing, trading, writing settlement and confirmation, and more. In this instance, Java's primary use is for server-side applications that receive and process data transferred between servers. Some institutions that use Java are:

  • Barclays
  • Citi Group
  • Credit Suisse

Big Data applications

Big Data refers to the analysis and systematic extraction of information from large and complex data sets. Some techniques include predictive modeling, machine learning analysis, and real-time stream processing. It is currently one of the most popular topics in the software industry. 

One of the most practical uses of the Java programming language is writing cloud development tools, frameworks, and libraries aimed at working with Big Data. The powerful memory management and features like automatic garbage collection make Java the preferred way for many programmers. Big Data tools that use it include:

  • Hadoop
  • Deeplearning4j
  • Spark

Pros and Cons Of Java Usage

No one can deny that Java is a powerful and effective programming language. And although many new scripts have debuted, Java still holds its own at the top. 

For nearly 30 years, nonetheless.

However, there are always two sides to a coin, and even if so widely used, Java is no exception.

So, why is Java so useful, and why is it not?

Let’s find out.


With Java being so ubiquitous, it's no surprise it has many positive aspects. 

It’s a simple, high-level language

Compared to other high-level languages, Java’s syntax is one of the simplest to learn, write, maintain, and understand. This allows for much easier code debugging and maintenance.  

One of the main goals of its creators was to make a language simpler than C and C++. 

Even though they based Java on these languages, they removed more complex features like explicit pointers concept, storage classes, operator overloading, etc. 

Platform Agnostic

The other main goal of Sun Microsystems was for Java to be highly portable, write once, and run anywhere language. Thanks to the virtual sandbox, the JVM, you can run anything written in Java on any machine, regardless of its operating system. This achieves the goal and makes for cheaper device integration and effective project management. 

Object-Oriented Programming Language

What you can do with Java is organize big modules into smaller objects and make them easier to manage, understand, and reuse. As such, the code is much more flexible and reusable, unlike procedural codes, which are more complicated to implement. 

Secure Language

By omitting explicit pointers, Java prevents risks of unauthorized access to its memory location. As an OOP language, it also allows developers to bind data and functions to a single unit and restrict access to it. Furthermore, Java provides a Security manager for each app which lets us define class access permissions. 

Supports Multithreading

A thread is the smallest unit of a process, and multithreading allows for maximum CPU utilization by running several independently from each other. Thanks to the threads’ shared memory, applications gain increased performance and efficiency. Multithreading support broadens the scope of what you can create with Java.

Java is a distributed language

Java provides a mechanism for sharing data and programs between multiple machines. It also supports Remote Method Invocation (RMI), enabling distributed processing. Thanks to Socket Programming and COBRA support, Java also shares objects in a distributed environment. This is one of the main reasons why businesses use Java.

Efficient Memory Allocation

Java’s memory allocation strategy primarily divides it into Heap Area and Stack Area. This allows the JVM to allocate memory from either of the two depending on requirements. 

Automatic Garbage Collection

As an automatic memory management tool that the JVM governs, this function automatically removes any object that doesn’t refer to a class from the program.

Huge Community and Regular Updates

Java has an immense community that supports its ongoing development. User groups frequently organize local meetups, providing peer learning and networking opportunities. The community also helps solve security issues by sharing experiences and support. 

Since Java’s been around for so long, troubleshooting solutions are just a Google search away. Among other organizations, one worth mentioning is OWASP. It’s an independent open-source foundation that provides guidelines and tutorials on dealing with the most widespread security risks when programming Java applications.


Although the benefits of Java are plenty, there are certainly some notable disadvantages.

Slow Performance

The additional work of the interpreter to convert the code to machine language and the fact that everything runs in the JVM sandbox instead of natively substantially hamper Java’s speed. Another factor is that automatic garbage collection constantly works in the background and uses extra resources.

Less attractive GUI builds

The GUI builder in Java is overall poor and limited for more complex UIs. Even frameworks aimed at this, like Swing and Java FX, aren’t advanced enough to handle more complex tasks that would be easily achievable in JavaScript or Python.   

No backup capabilities

A significant drawback is that Java works from storage and doesn’t provide any backup.

Verbose code

Although Java programming languages are simple, coding sentences can become quite long and complex to follow or remember.

Most Used Java Frameworks

A framework in Java is a set of classes, tools, and related components that help develop a project.

What framework you choose to use depends on the project type. For example, if you want to build a web app, you’ll pick one rich in related tools. 

The vast number of frameworks and libraries is partly why many use Java. Here are some prominent ones:

  • Spring - Any Java application can use this framework. It includes Inversion of Control (IoC), which does object coupling at runtime rather than during compiling. It also provides Dependency Injection, which works in conjunction with the former and allows loose coupling by supplying object dependency. A package in itself, it implements configuration and security features.
  • Hibernate - Hibernate makes handling databases with Java easier. With its Object-Relational Mapping (ORM), it solves problems regarding JDBC, which doesn’t support object-level relationships. It maps database tables to the appropriate Java classes directly by creating abstraction layers. This way, the code can be loosely coupled. Hibernate handles database connections or related operations on its own, so developers don’t have to think about it. 
  • Apache Struts - This is an open-source framework used for web applications. It follows the MVC (Model-View-Controller) pattern design that divides model, view, and controller and binds them through the struts-config.xml file. Struts has various plugins and supports AJAX, REST, and JSON. It is more flexible and sets up quicker than traditional MVC architecture.
  • Google-Web Toolkit - This is a very developer-friendly framework because it makes working with Google APIs much easier. Thanks to its ability to convert Java bytecode into JavaScript code based on a browser, it is highly favored. This framework supported the development of Google products like AdSense and Google Wallet.

Learning Java Programming

By now, it should be apparent how useful Java is

Thanks to its simplicity, wide range of use, and the large community and resources available, it’s a language worth considering.

Pretty much any business imaginable is in need of Java developers, so employability rates are high. This is especially true, considering that most business requires a mobile app, specifically an Android one. 

That is, of course, if your coding chops are up to snuff.

There are many high-quality courses online and available for anyone - just make sure it is up to date.

The programming world is ever-evolving, and you don’t want to waste time and money learning how to work with something redundant. For example, Java 8 was released in 2014 and completely changed how the language was written. While between September 2019 and September 2020, Java released versions 13, 14, and 15.

When learning how to use Java, use the latest version or one with Long Term Support (LTS). Businesses are more likely to use the latter since frequent updating is a big hassle when involving large setups.

Also, keep in mind that Java’s core is the same, and all the previous releases are compatible.  

Here are a few options from some of the top online learning platforms you may wish to consider:

The Complete Java Masterclass on Udemy

This is probably the most popular course on Udemy. It has over 670,000 enrolled students and a rating of 4.6 stars from over 160,000 reviews. 

It is a comprehensive course with over 80 hours of video material covering OOP, Core Java Fundamentals, Multithreading, etc. It also features numerous practical tasks so you can start programming a Java application quickly.

Major businesses like Volkswagen and Eventbrite have offered this course to their employees, so you know it’s a good one.

Furthermore, the instructor keeps the course current and updates it when necessary. The latest one is from February 2022.

Java 17 Essential Training: Syntax and Structure on LinkedIn Learning

This course quickly gained popularity on the LinkedIn Learning platform.

Along with it being current, it starts you off by setting up both the JDK and the IntelliJ Community Edition IDE. This is a great benefit, as it’s considered good practice to start working with IDEs sooner rather than later.

Although it’s a reasonably short course, the instructor goes through all the fundamentals like OOP, variables, data types, classes, loops, and even covers array and text processing.

It’s an excellent place to start and acquaint yourself with the basic uses of the Java programming language.

Java Programming and Engineering Fundamentals on Coursera

This fantastic course offered by Duke University on Coursera teaches core concepts and equips you with the tools needed to start writing programs and solve complex problems. Specially geared towards complete beginners, it provides you with a solid foundation to solve real-world problems like algorithm designing, testing, and debugging.

The course spans over five months, and although it’s subscription-based, you can pause it anytime and continue later. 

On completion, you can also receive a legitimate certificate which will serve you well on job applications.

Wrap Up

So, what is Java used for?

It can be used for pretty much anything to various extents. 

Java is a programming language that has stood the test of time and only continues to evolve and grow. 

Even though it has its share of disadvantages, its flexibility, portability, power, and security still make it one of the most sought-after software programming solutions.  

If you’re looking to become a developer, Java is undoubtedly one of the best places to start. 

If you’re already one and looking to expand your abilities and portfolio, this is one of your best options.


Velina Nenova

Velina Nenova

Velina describes herself as passionate media savvy and a versatile individual with numerous different interests, most a result of her Media & Communications BA. She has also developed a keen interest in Digital Marketing and Advertising. Her never-ending desire to constantly learn new things and enrich herself and her ultimate dream to go around the globe before 45 are her driving forces.

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