JDK, JRE, and JVM are all key components of the Java programming language, each serving a specific role in the Java development and execution process:
JDK (Java Development Kit):
The JDK is a software development kit that includes tools and resources necessary for developing Java applications.
It contains the Java compiler (javac), debugger, libraries, documentation, and other utilities needed for Java development.
Developers use the JDK to write, compile, and debug Java code.
JRE (Java Runtime Environment):
The JRE is a part of the JDK but can also be installed separately.
It provides the runtime environment for Java applications to run. It includes the Java Virtual Machine (JVM), class libraries, and other files that support the execution of Java applications.
Users who only want to run Java applications, without the need for development, typically need the JRE.
JVM (Java Virtual Machine):
The JVM is an abstract machine that provides a runtime environment for Java bytecode to be executed.
When a Java program is compiled, it is translated into bytecode, which is then interpreted and executed by the JVM.
The JVM is platform-dependent, meaning there are different implementations for different operating systems. It abstracts the hardware and operating system details, allowing Java programs to be executed in a "write once, run anywhere" manner.