Getting output from java program is
two step procedure, compilation and interpretation. Output of java compiler is
not executable code but it is compiled code. JVM is an interpreter for byte
code. Byte code is set of instructions which are to be executed by java run
time system called as Java Virtual Machine (JVM). Each JVM has its own
executable format so this byte code (.class file) becomes platform independent
as this byte code runs on JVM and not on actual OS.
So once we have compiled java
program, it can be executed on any platform. The details of the JVM differ from
platform to platform and each OS has its own JVM format. So in java it is “write once; run anywhere,
anytime”.
So java is platform independent and JVM is highly platform
dependent.
