Terminology - machine code and byte code

Do "machine code" and "byte code" terms refer to the available instruction set to the CPU and virtual CPU and their encoding (the language specification) or do they refer to the "encoding" of the current program's instructions after compilation?

The definitions I found in wikipedia seem to lean towards the notion of "instruction set":

• https://en.wikipedia.org/wiki/Machine_code

• https://en.wikipedia.org/wiki/Bytecode

Both are sequence of instructions encoded as binary data. The difference being that "Machine code" is executed by the CPU whereas "byte code" is executed by a software (which itself is made up of machine code and executed by CPU).

StackExchange Computer Science Q#57392, answer score: 4