Java code is stored in bytecode, and then JIT compiled to translate bytecode to machine code. That introduces a delay before a running a code, when bytecode is compiled to machine code, but improves speed of execution compared to direct interpretation of the source code. Generated by the compiler, Bytecode is the type of machine language for JVM. JVM loads a class file and gets byte codes for each method in the class and are stored in the method area of the JVM and executed when that method is invoked during the course of running the program. They can be executed by interpreter, just-in-time (JIT), or any other technique that was chosen by the user of JVM.
