What is the difference between JDK, JRE and JVM

JVM (Java Virtual Machine): It is the responsible for run the Java program line by line. It is an abstract machine which provides the runtime environment in which java bytecode can be executed.
Note: JVMs are platform dependent but java is platform independent.

JRE (Java Runtime Environment): Only run the Java application. It is the implementation of JVM and it is physically exists. It contains set of libraries (ex: rt.jar etc) + other files that jvm uses at runtime.

JDK (Java Development Kit) : Develop and run the Java applications. It physically exists. It contains JRE + development tools like javac, java ...etc.