All you Should Know about Java Runtime Environment

Libraries, the Java Virtual Machine, and other elements are included in the Java Runtime Environment (JRE), which is required to run applets and programs created in Java. The JRE also comes with two crucial deployment technologies: Java Web Start, which distributes standalone applications over a network, and Java Plug-in, which enables applets to run in popular browsers. The official Java download page for Sun Microsystems can be found here.

What is the Java Runtime Environment (JRE)?

The class libraries and other resources needed to run a Java application are provided by the Java Runtime Environment, or JRE, a layer of software that runs on top of the operating system software on a computer.

One of three related components required to create and execute Java programs is the JRE. As for the final two elements, they are as follows:

  • A set of instruments for developing Java applications is called the Java Development Kit (JDK). Developers select JDKs based on the Java version and the package or edition—Java Mobile Edition (JME), Java Special Edition (JSE), or Java Enterprise Edition (JEE) (Java ME). Every JDK includes a suitable JRE since executing a Java application is a necessary step in the development process.
  • Real Java applications must run on the Java Virtual Machine, or JVM. Every JRE comes with a default JRE, but programmers can choose another that better suits the resource needs of their particular applications.

The JRE creates a JVM instance that runs the application created by combining Java code created using the JDK with the necessary libraries. Programs created with the JRE will run on all of the JVMs that are available for a range of operating systems. In this sense, the Java Runtime Environment is what enables a Java application to run unchanged in any operating system.

How does JRE work?

Together, the JDK and JRE create a robust runtime environment that enables Java-based programs to operate on almost any operating system. The following elements make up the JRE runtime architecture:


The Java ClassLoader dynamically loads every class needed to run a Java application. The JRE uses ClassLoaders to automate this procedure because Java classes are only loaded into memory when they are required.

Checker for Bytecode

The bytecode validator validates Java code before sending it to the interpreter and verifies its accuracy. The class will not be loaded if the code compromises system integrity or access rights.


The Java interpreter creates an instance of the JVM after successfully loading the bytecode, enabling the Java application to run natively on the underlying computer.

What components make up JRE?

To help you get the most out of your Java applications, JRE also contains a number of different supplementary software tools and features in addition to the Java Virtual Machine.

Alternatives to deployment

The deployment technologies included in the JRE installation, such as Java Web Start and Java Plugin, make it easier to activate applications and offer cutting-edge compatibility for next Java versions.

A set of developer tools

The JRE also comes with toolkits to help programmers enhance their user interface. These toolkits include:

  • Drawing two-dimensional pictures is made possible through the Java 2D Application Programming Interface (API). Developers can produce interactive user interfaces, unique effects, interactive games, and animations.
  • The Abstract Window Toolkit is a GUI (Graphical User Interface) for creating objects, buttons, scroll bars, and windows (AWT).
  • Swing: A different lightweight GUI that uses a wide variety of widgets to provide user-friendly customizations.

Integration libraries

To assist developers in building efficient data connections between their applications and services, the Java Runtime Environment comes with a number of integration libraries. These libraries include:

  • By employing the Common Object Request Architecture, Java IDL (CORBA) supports distributed objects created in the Java programming language.
  • The Java Database Connectivity (JDBC) API enables programmers to build applications with distant relational databases, flat files, and spreadsheets as data sources.
  • Java Name and Directory Interface (JNDI): A naming conventions-based programming interface and directory service that enables users to create portable programs that access data from databases.

Language and utility libraries

The JRE comes includes the java.lang and java.util packages, which are crucial for Java application design, package versioning, management, and monitoring. These bundles include:

  • Collections Framework: A cohesive framework made up of a number of interfaces designed to enhance the processing and storing of application data.
  • High-performance threading tools are part of the comprehensive framework bundle known as Concurrency Utilities.
  • Preferences API: A compact, cross-platform persistent API that lets several users on the same machine build their own set of program preferences.
  • Logging: Produces log reports for additional investigation, including security lapses, configuration errors, and performance issues.
  • Java Archive, or JAR a file format that is independent of platforms that enables several files to be compressed into a single JAR file, dramatically accelerating download times.

Java Runtime Environment in brief

After reading numerous references, we compiled the following commonly asked questions regarding downloading the Java Runtime Environment. Let's examine each one separately.

What Is Java Runtime Environment, Exactly?

JRE, short for Java Runtime Environment, is a free software download from Oracle. It is necessary for your system to run Java apps or programs. In other words, before a programmer can use the Java command to launch a Java application, JRE must be installed on the computer.

JRE is also used for JDB (Java Debugging), which allocates Java objects dynamically from heap space. It includes a wide range of auxiliary software features and tools, including development toolkits, integration libraries, language and utility libraries, deployment solutions, and libraries for these purposes.

What Distinguishes JRE, JDK, and JVM from One Another?

However, the differences between JDK, JRE, and JVM confuse a lot of consumers. Which one to select is up for debate. We'll help you separate them from the following elements.

Their Java-based Use:

  • JRE is a software package that provides an environment for Java apps and programs. End users who just wish to run Java programs on the system are its main consumers.
  • The name Java Development Kit (JDK) refers to a software environment for developing and running Java programs. It comes with a variety of tools for executing, debugging, and compiling Java-based projects.
  • JVM, short for Java Virtual Machine, is responsible for loading, verifying, and running Java bytecode. It performs similar tasks to an interpreter or the Java programming language's core.


  • Deployment solutions, development toolkits, integration libraries, and language and utility libraries make up the four areas of JRE. Each component, of course, includes a wide variety of sub-toolkits, features, and libraries.
  • JDK: It contains all of the Java development environment tools, executables, and binaries required to run Java programs, including a JRE, a debugger, a compiler, an archiver, and other tools.
  • Runtime Data Areas, Class Loader Subsystem, and Execution Engine are the three parts or subsystems that make up the JVM.

JRE, JDK, and JVM relationships

JRE is in charge of running the Java program, whereas JDK is the development platform that includes JRE. The Java Virtual Machine (JVM) serves as the foundation or core element of the Java programming language, guaranteeing that Java application source code is cross-platform. Furthermore, Java programs cannot run without JVM because it is necessary for both JDK and JRE.

My machine has JRE installed, right?

Check to see if JRE for Windows 10/11 is already installed before downloading it. Here is one instance.

Step 1: Type cmd into the search bar, then click the Command Prompt program and choose Run as administrator from the context menu.

Step 2: Type java -version and hit Enter in the elevated Command Prompt window. The JRE and installed version of Java can then be seen. An error message that reads "java" is not recognized as an internal or external command, operable program, or batch file may indicate that your computer does not have the Java JRE installed or that it is corrupt. The steps below will help you download and install Java JRE.

run java version command

Download and installation instructions for Java Runtime Environment for Windows 10 and 11

JRE is a necessary component for running Java programs, as was already mentioned. If you don't have the JRE downloaded, you can experience problems like Jar files not opening, the Lunar client crashing, and so on. The Java Runtime Environment must be explicitly downloaded and installed in this case.

Oracle does not offer a standalone Java JRE download package for users; instead, it is part of the JDK package. Therefore, download the Java JDK package and install it on Windows 10 or 11 to obtain JRE. Of course, a few independent websites provide the Java Runtime Environment as a single download package. You can download JRE from these websites if you don't mind.

install Java Runtime Environment

Step 1: Click here to open the Oracle Java Downloads page. Scroll down to the Windows tab and click the appropriate download link. Depending on your needs, pick one of the three JDK download packages.

Step 2: After downloading, you will get the JDK and JRE packages. Double-click the JRE executable file and choose Yes to launch it.

Step 3: To start installing the Java Runtime program, click Install in the Java Setup box. Before clicking Close, wait for the installation to be finished.