JDK, JRE and JVM

    JDK (Java Development Kit), JRE (Java Runtime Environment), and JVM (Java Virtual Machine) are fundamental components of the Java programming language. Each plays a distinct role in the development and execution of Java applications.

1. JDK (Java Development Kit):

   • The JDK is a software development kit used for developing Java applications.
   • It includes the Java Compiler (javac), which translates Java source code into bytecode.
   • The JDK also provides various tools and utilities for development, debugging, and profiling.
   • Additionally, it includes the JRE, so if you have the JDK installed, you also have the JRE.

2. JRE (Java Runtime Environment):

   • The JRE is a runtime environment that allows Java applications to run on a computer.
   • It includes the Java Virtual Machine (JVM), class libraries, and other necessary files.
   • The JRE is sufficient for running Java applications but lacks the development tools and utilities provided by the JDK.
   • If you only want to run Java applications and do not plan to develop them, you can install the JRE.

3. JVM (Java Virtual Machine):

   • The JVM is a virtual machine that executes Java bytecode.
   • It provides an abstraction layer between the compiled Java program and the underlying hardware and operating system.
   • Java source code is compiled into bytecode, which is platform-independent and can be executed by any JVM.
   • The JVM manages memory, performs garbage collection, and ensures the proper execution of Java programs.

In summary, the JDK is for Java development and includes the JRE, which is for running Java applications. The JVM is the runtime environment responsible for executing Java bytecode on a specific platform.