First time I see this. I understand jack of it but it's really amazing. On one side, it seems not too different from an abacus (it's just a machine!), on the other side there's a connection to the processor that I use right now. Very cool.
If you connect billions of switches in the right pattern you get a computer. Billions of little switches clicking on and off, no more, no less. No pixies or magic dust involved.
http://www.righto.com/2013/01/a-small-part-of-6502-chip-expl...
(I love linking people to this article. It's one of my favorite things I've ever read.)