JVM stands for Java Virtual Machine.JVM is platform where Java programs are executed. without JVM we can’t execute java programs. Java program generate output in bytecodes and that bytecodes are executed in JVM. We don’t need to compile java programs again and again for different platforms, because JVM is available for all platforms. Set of Registers,Garbage heap size,method area are specified inside JVM, and JVM tells java programs about these specifications which will be allocated to each program.A Java virtual machine can either interpret the bytecode one instruction at a time (mapping it to a real processor instruction) or the bytecode can be compiled further for the real processor using what is called a just-in-time compiler.

What JVM does ???

  1. JVM loads the code.
  2. JVM verify the code.
  3. JVM executes the code.
  4. JVM provides Runtime Environment.
  5. JVM Provide Memory area for java programs.
  6. JVM Register set.
  7. JVM provide garbage heap size to java program.
  8. JVM provide fatal error reporting