JVM JRE JDK

JVM (Java Virtual Machine)

           As we all aware when we compile a Java file, output is not an ‘exe’ but it’s a ‘.class’ file. ‘.class’ file consists of Java byte codes which are understandable by JVM. Java Virtual Machine interprets the byte code into the machine code depending upon the underlying operating system and hardware combination. It is responsible for all the things like garbage collection, array bounds checking, etc… JVM is platform dependent.

JRE (Java Runtime Environment)

   
          Java Runtime Environment contains JVM, class libraries, and other supporting files. It does not contain any development tools such as compiler, debugger, etc. Actually JVM runs the program, and it uses the class libraries, and other supporting files provided in JRE. If you want to run any java program, you need to have JRE installed in the system.

JDK (Java Development Kit)

   
         Java Development Kit is a superset of the JRE, and contains everything that is in the JRE, plus tools such as the compilers and debuggers necessary for developing applets and applications.