Java Virtual Machine (JVM):

All language compilers translate source code into machine code for a specific computer. But, Java compiler produces an intermedia code known as bytecode for a machine that does not exist. This machine is called the Java Virtual Machine and it exists only inside the computer memory. It is a simulated computer within the computer and does all major functions of a real computer

The virtual machine code is not machine specific. The machine specific code (known as machine code) is generated by the Java interpreter by acting as an intermediary between the virtual machine and the real machine. The interpreter is different for different machines.