What are JVM, JDK, and JRE?

JVM (Java Virtual Machine) - a virtual machine that executes Java bytecode. It ensures Java's cross-platform compatibility.

JRE (Java Runtime Environment) - the Java runtime environment, including JVM, standard Java class libraries, and auxiliary files. It does not contain development tools.

JDK (Java Development Kit) - a developer kit that includes JRE, Java compiler (javac), debugger (jdb), and other utilities for creating, compiling, and debugging Java applications.

The relationship between them:

• JDK includes JRE.
• JRE includes JVM.

Thus:

• JVM: Executes bytecode.
• JRE: Provides an environment for running Java applications (includes JVM).
• JDK: Provides tools for Java application development (includes JRE).