FYI, Minecraft is in Java, not Javascript. As mentioned before, they're very different languages entirely.

Javascript, originally developed by Netscape (now Mozilla), can basically be thought of as an add-on to HTML. It only runs in a browser, and it adds limited functionality to web pages.

Java, originally developed by Sun (acquired by Oracle), is a full-function, object-oriented programming language that can be used to write entire applications from the ground up. It runs within its own java virtual machine (JVM), which abstracts the application code from the OS and hardware of the machine it's running on. This makes any Java application fully portable from one machine type to another with no changes to the program code. You just have to install the correct JVM, and it interprets the program calls into the appropriate system calls.

Java is a pretty complicated beast to tackle, and as a first programming language, I'd recommend your DS's choice of Python over it.

And big kudos to him for deciding to learn to actually write programs!