Comment by robotguy

Ben Eater's Youtube series "Building an 8-bit Breadboard Computer" is a really good introduction to the lowest levels of how a computer works:

https://www.youtube.com/playlist?list=PLowKtXNTBypGqImE405J2...

I recommended it to my daughter when she was taking a class in R and asked "But how does the COMPUTER know what to do?"