Class File Each .class file contains the definition of a single: class interface or a module Class format (the specific order and meaning of bytes) described in the spec not neceserily applies to an actual file on the filesystem: those “bytes” might have been read from the database, downloaded from the web or constructed by a class loader; keep this in mind whenever you encounter the phrase “class file format”.

Overview of JVM compilation - with samples and links to various interpreters on GitHub

How to learn JVM? Is reading The JVM Specification a good idea? Here are some tips on how to approach JVM learning process.