- java is for general questions about the Java programming language.
- jvm is for questions related to implementation of a virtual machine that is running Java programs.
Yeah, those aren't the same thing. I removed the synonym. Luckily the two tags were never merged, so 3978 jvm questions from before the synonym was created weren't retagged. About 100 were retagged while the synonym was active, so at least the damage was minimal. Thanks for bringing this to our attention.