☛ JVM: JVM stands for ‘Java Virtual Machine’ is an abstraction for a machine in Java. This is the necessary abstraction environment necessary for the Java bytecode to be executed in. A runtime instance of the virtual machine is incepted whenever the java command is executed on the command prompt.

☛ JRE or ‘JAVA Run-time Environment’ is the very environment, which implements the JVM by providing class files and libraries it uses to run the bytecode at runtime. In essence, this is a software instance of the JVM, which unlike the JVM has a physical existence.

☛ JDK is the superset here, which engulfs and contains JRE and is really a framework where compilation and documentation of Java programs are performed into packages.