Is the JVM a compiler or an interpreter?

Question

I have a very basic question about JVM: is it a compiler or an interpreter?

If it is an interpreter, then what about JIT compiler that exist inside the JVM?
If n

Answer 1

Like @delnan already stated in the comment section, it's neither.

JVM is an abstract machine running Java bytecode.

JVM has several implementations:

• HotSpot (interpreter + JIT compiler)
• Dalvik (interpreter + JIT compiler)
• ART (AOT compiler + JIT compiler)
• GCJ (AOT compiler)
• JamVM (interpreter)

...and many others.

Most of the others answers when talking about JVM refer either to HotSpot or some mixture of the above approaches to implementing the JVM.

Answer 2

It is both. It starts by interpreting bytecode and can (should it decide it is worth it) then compile that bytecode to native machine code.