Once write run every where ?

Question

once we write we can use that program any where how

Answer 1

well Java is portable , means that you can run Java bytecode on any hardware that has a compliant JVM (Java Virtual Machine).
Java is execute in byte codes which is able to interact with Any hardware
The Java Compiler compiles a java program (.java file) and converts it into class files (.class) that contain bytecodes , which is the intermediate language between source code and machine code . These bytecodes are not platform specific, so with the help of JVM (Java virtual machine), the java program can run on wide variety of platforms. The JVM (Java virtual machine) is platform dependent i.e its implementation differs from platform to platform (like windows, linux atc.), but these all JVMs can execute the same javabytecode .