Instructions are basically numbers. The width of those numbers (e.g. 8-bit, 16-bit, etc) depend on the architecture. ARM instructions can be 16-bit, 32-bits wide or 64-bit wide, depending on which ...

The JVM manages code compilation and optimization, so you don’t have to worry about machine instructions and the optimal way of writing application code for an underlying platform architecture.

The machine code is saved and stored separately to the high-level code. Compilation is slow, but machine code can be executed quickly. Java and C++ are examples of compiled programming languages.

Machine code instructions are structured slightly differently by different processor manufacturers and for different operating systems. You have to totally re-write a program if you want it to run ...