What does java virtual machine does actually?

Answer 1

Look, You know that the code we write in high level languages must be converted to machine understandable language. Now this machine language is machine dependent, so the code will have to be compiled for every machine on which it runs.

In case of Java the JVM acts as a middle ground. The Java Virtual Machine acts as a machine itself. We write code which gets compiled into Java Byte Code for the JVM. Since this JVM will be common, same code can run across multiple platforms. JVM then executes the program

Answer 2

in short run the program.it runs that by translating the bytecode generated after compile into a language that actual machine understands.
it acts like the machine to run program