>>717190304
It's time to remember SICP. It explains better than I could.
Someone gets the computer to do addition. It becomes le blackbox. You don't have to invent addition yourself, someone did it.
Now I want multiplication. I make the computer do multiplication by using addition many times. It's a blackbox. Or abstraction. I know how I did multiplication, but someone using my set of circuits doesn't have to. They can call this blackbox of multiplication instead of doing the addition or not rly know it.