Comment by WorldMaker

I think the most ELI5 approach is Alligator Eggs [0] which was built for 8-year-olds to play like a game. You can find a lot of the advanced concepts outside of the core also explained in terms of Alligator Eggs and some software visualizers, but there's also something to be said about hands on learning and about printing it out yourself on some cardstock or cardboard paper, cutting it out, personalizing it with crayons, and playing it with a child or at least your inner child.

[0] https://worrydream.com/AlligatorEggs/