JDK , JRE , JVM

Home / Core Java / JDK , JRE , JVM

JDK , JRE , JVM

 Difference between JDK, JRE, and JVM 

 Before exploring the specifics of Java development, it's essential to understand the core components: JDK, JRE, and JVM. 


JDK (Java Development Kit):

The JDK is a software development kit used to develop Java applications. It includes a set of tools necessary for developing, compiling, debugging, and running Java programs. The key components of JDK include:

  • Java Compiler (javac): Converts Java source code (.java files) into bytecode (.class files).
  • Java Virtual Machine (JVM): Executes Java bytecode.
  • Java Runtime Environment (JRE): Provides libraries, APIs, and other components required to run Java applications.

The JDK comprises the JRE as well as development tools like compilers, debuggers, and other resources required for software development.


JRE (Java Runtime Environment):

The JRE is an environment that provides the minimum resources required for executing Java applications. It includes the JVM, libraries, Java class libraries, and other components necessary to run Java applications but does not contain development tools such as compilers and debuggers. It consists of:

  • Java Virtual Machine (JVM): Executes Java bytecode.
  • Java Class Library: A set of prebuilt classes for common programming tasks.
  • Support Files and Libraries: Required files and libraries to run Java applications.

JRE is intended for users who want to run Java applications but do not need development capabilities.



JVM (Java Virtual Machine):

The JVM is an abstract machine that provides the runtime environment in which Java bytecode can be executed. It abstracts the underlying hardware and operating system, allowing Java programs to be platform-independent. The JVM performs several essential functions:

  • Loads and executes bytecode: Reads and interprets compiled Java bytecode.
  • Memory Management: Manages memory allocation, including garbage collection.
  • Provides Runtime Environment: Facilitates the execution of Java applications.

The JVM is specific to each operating system and translates Java bytecode into machine-specific instructions at runtime. It is responsible for executing Java programs by running the bytecode.