JVM in PyLucene

Question

I am planning to use PyLucene as a tokenizer in my project. It is mentioned in PyLucene homepage that it allows python to make calls to Java classes directly via JNI interface. Also, before making calls to Java classes, we first need to call initVM().

1. What initVM() does here? Does it launch a new JVM process or is it the part of calling/hosting python process?
2. How are the calls I make in python to Java classes being processed in JVM?
3. If initVM() is launching a new process, Is there a communication going over process boundary between calling/hosting python process and JVM?
4. If JVM is part of the calling/hosting process, what is its lifecycle and how it is bound to the calling/hosting python process?