Java internals

Question

What exactly are the topics that come under internal working of java? Is it just the complete working of JVM or is there something more to it?

A couple of websites I visited just explain about JVM. So I just want to know if there is something that I'm missing.

Answer 1

Everthing about jvm

https://proandroiddev.com/android-cpu-compilers-d8-r8-a3aa2bfbc109

Answer 2

Sumit Programmer😎😎 my question was whether is it only the JVM that we have to learn about if we want to learn the internal working of a whole java program or is there something else we should know.