It's more like wiring together a series of tubes. The signal has to propagate from one end of the tubes to the other in a single clock cycle. Note that the tube

It's more like wiring together a series of tubes. The signal has to propagate from one end of the tubes to the other in a single clock cycle. Note that the tubes can go backwards, so you can feed the output of the tube into the next input of itself. Hardware programming like this is actually extremely fun, but for some reason the widely available languages for doing it suck. And make what is going on in the hardware opaque and difficult to understand for any non trivial applications. (We're talking 100000s of lines of code to do anything nontrivial).