What is JDK and JRE?

• JDK (Java Development Kit): A set of tools for Java development. Includes JRE, the javac compiler, the jdb debugger, the utility for creating executable JAR files jar, and other tools. Necessary for writing and compiling Java code.
• JRE (Java Runtime Environment): The Java runtime environment. Includes JVM (Java Virtual Machine) and standard Java class libraries (Java API). Allows running compiled Java programs (.class files). Needed by end-users to run Java applications, but not for development.

Main differences:

JDK	JRE
For developers	For end-users
Includes JRE	Includes JVM and standard libraries
Allows code compilation	Only allows code execution
Larger size	Smaller size

// Example of using JDK for compilation
// javac MyProgram.java

// Example of running a compiled program with JRE
// java MyProgram