#23 JDK, JRE, JVM in JAVA | Skyhighes | Lecture 23

JDK, JRE, and JVM are crucial components in the Java ecosystem, and understanding their differences is essential for any Java developer. Here's a breakdown:

1. JDK (Java Development Kit):

Purpose: Development environment for building Java applications.
Components:
JRE (Java Runtime Environment): Provides classes and libraries needed to run Java applications.
Java compiler (javac): Converts Java source code (.java files) into bytecode (.class files).
Java archiver (jar): Packages classes and resources into JAR files for deployment.
Other tools: Class documentation generator (Javadoc), debugger (jdb), appletviewer, etc.
2. JRE (Java Runtime Environment):

Purpose: Execution environment for running Java applications.
Components:
JVM (Java Virtual Machine): Virtual machine that interprets and executes Java bytecode.
Standard libraries: Classes and APIs needed for common tasks like I/O, networking, and GUI development.
3. JVM (Java Virtual Machine):

Purpose: Platform-independent abstraction that executes Java bytecode.
Concept:
Java code is compiled into bytecode, which is machine-independent.
JVM interprets and executes bytecode on any operating system with a compatible JVM implementation.
Provides memory management, garbage collection, and security features.
Relationships:

JDK contains JRE and additional development tools.
JRE contains JVM and standard libraries.
JVM interprets Java bytecode regardless of source platform.
Choosing the right one:

JDK: Choose if you need to develop Java applications.
JRE: Choose if you only need to run compiled Java applications.
Additional Resources:

I hope this clarifies the differences between JDK, JRE, and JVM. Feel free to ask if you have any further questions!