JDK vs. JRE: What's the Difference?

Edited by Sawaira Riaz || By Sumera Saeed || Updated on October 4, 2023
JDK (Java Development Kit) is a software package for developing Java applications; JRE (Java Runtime Environment) is for running them.

Key Differences
JDK, which stands for Java Development Kit, is the complete toolset provided by Oracle (and other vendors) for programmers to create, compile, and debug Java applications. Within the JDK, there's an included JRE, ensuring that developers can run the Java applications they create.

Sumera Saeed
Oct 04, 2023
JRE, or Java Runtime Environment, on the other hand, is a subset of JDK. It's what gets installed on a machine to allow a pre-developed Java application to run. JRE does not contain tools for Java development; it only provides the necessary runtime environments such as class libraries, JVM, and other necessary components.

Sumera Saeed
Oct 04, 2023
At a more granular level, JDK provides utilities like the Java compiler (javac) which converts source code into bytecode. JRE then takes this bytecode and uses the Java Virtual Machine (JVM) to interpret or compile it at runtime. This bifurcation ensures that development and runtime environments can exist independently, allowing for flexibility in deployment and development.

Sumera Saeed
Oct 04, 2023
In simple terms, if you're a developer wanting to create a Java application, you would need the JDK. However, if you're an end-user wanting only to run a Java application on your machine, the JRE would suffice. This distinction makes Java both a versatile and accessible platform, catering to both developers and users.

Sumera Saeed
Oct 04, 2023
A common analogy to understand JDK and JRE is to consider the JDK as a kitchen where meals (Java applications) are prepared, whereas the JRE is the dining table where meals are consumed but not created.

Aimie Carlson
Oct 04, 2023
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Comparison Chart
Definition
Java Development Kit: suite for developing Java applications
Java Runtime Environment: to run Java applications

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Oct 04, 2023
Components Included
Compiler, debugger, JRE, and more
JVM, Java Class Libraries

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Oct 04, 2023
Main Function
Develop, compile, and debug Java applications
Execute Java applications

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Oct 04, 2023
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JDK and JRE Definitions
JDK
JDK contains tools like compilers and debuggers.
Using the JDK, developers can debug their Java applications.

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Oct 04, 2023
JRE
JRE doesn't have development tools.
You cannot compile Java applications using only the JRE.

Sumera Saeed
Oct 04, 2023
JDK
JDK includes JRE for running applications.
After developing an app with the JDK, you can run it using the bundled JRE.

Sara Rehman
Oct 04, 2023
JRE
JRE is a subset of JDK.
While the JDK is for developers, the JRE caters to end-users.

Janet White
Oct 04, 2023
JDK
JDK is essential for comprehensive Java programming.
Sophisticated Java projects necessitate the complete toolset provided by the JDK.

Harlon Moss
Oct 04, 2023
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JRE
JRE provides the runtime environment for Java.
Java applications run on computers with the JRE installed.

Sumera Saeed
Oct 04, 2023
JDK
JDK is a suite of tools for Java development.
To develop a Java application, one needs the JDK.

Sumera Saeed
Oct 04, 2023
JRE
JRE allows pre-written Java applications to function.
To execute a Java-based game, one would install the JRE.

Sumera Saeed
Oct 04, 2023
JDK
JDK is used for creating Java applications from scratch.
Without the JDK, Java development would be impossible.

Sumera Saeed
Oct 04, 2023
JRE
JRE contains JVM and core libraries.
The JRE ensures that Java applications run consistently across devices.

Sawaira Riaz
Oct 04, 2023
FAQs
Do I need JDK to run a Java application?
No, to run a Java application, only JRE is required. JDK is for development.

Sumera Saeed
Oct 04, 2023
Is JDK platform-independent?
Java's code is platform-independent, but JDKs are platform-specific as they contain tools and binaries for specific systems.

Harlon Moss
Oct 04, 2023
How does JRE differ from JDK?
JRE provides the environment to run Java applications, while JDK is used for both development and execution of Java apps.

Sawaira Riaz
Oct 04, 2023
Can I develop Java applications using only JRE?
No, Java development requires the tools found in JDK.

Sumera Saeed
Oct 04, 2023
What's the role of the javac tool?
javac is the Java compiler in JDK; it converts source code into bytecode.

Aimie Carlson
Oct 04, 2023
Is it possible to have multiple versions of JDK or JRE installed?
Yes, one can have multiple versions installed, but managing paths and compatibility is crucial.

Sumera Saeed
Oct 04, 2023
What is JDK?
JDK, or Java Development Kit, is a software toolkit used for developing Java applications.

Sumera Saeed
Oct 04, 2023
Is the JVM the same in both JDK and JRE?
Yes, the JVM component within JRE remains the same whether it's standalone or within JDK.

Sumera Saeed
Oct 04, 2023
Why is Java called 'Write Once, Run Anywhere'?
Java's bytecode can run on any system with the appropriate JRE, making the code platform-independent.

Harlon Moss
Oct 04, 2023
Do I need to pay for JDK or JRE?
While Oracle provides a commercial JDK, there are also free, open-source versions available. JRE is typically free.

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Oct 04, 2023
Why does JDK include JRE?
JDK includes JRE to allow developers to run and test the applications they develop.

Harlon Moss
Oct 04, 2023
Which one is bigger in size, JDK or JRE?
JDK is larger as it contains all components of JRE plus development tools.

Sumera Saeed
Oct 04, 2023
If I update my JDK, does the JRE also get updated?
Yes, updating JDK will update the bundled JRE.

Harlon Moss
Oct 04, 2023
Are there different versions of JDK and JRE?
Yes, both JDK and JRE have multiple versions, often corresponding to different versions of Java.

Aimie Carlson
Oct 04, 2023
What's JVM's role in JDK and JRE?
JVM, or Java Virtual Machine, is part of JRE and executes the Java bytecode.

Aimie Carlson
Oct 04, 2023
Why might someone install only JRE and not JDK?
An end-user who only wants to run Java applications, without developing them, would need just the JRE.

Sumera Saeed
Oct 04, 2023
Do all Java developers need JDK?
Yes, if you're developing Java applications, the JDK is essential.

Sumera Saeed
Oct 04, 2023
How do I know if I have JDK or JRE installed?
You can use command-line tools like java -version and javac -version to check for JRE and JDK installations, respectively.

Janet White
Oct 04, 2023
About Author
Written by
Sumera SaeedSumera is an experienced content writer and editor with a niche in comparative analysis. At Diffeence Wiki, she crafts clear and unbiased comparisons to guide readers in making informed decisions. With a dedication to thorough research and quality, Sumera's work stands out in the digital realm. Off the clock, she enjoys reading and exploring diverse cultures.

Edited by
Sawaira RiazSawaira is a dedicated content editor at difference.wiki, where she meticulously refines articles to ensure clarity and accuracy. With a keen eye for detail, she upholds the site's commitment to delivering insightful and precise content.
