The way it was explained to me is that when you "farm" your "plots" the first time, you are just generating and writing a lot of numbers that are written in the

The way it was explained to me is that when you "farm" your "plots" the first time, you are just generating and writing a lot of numbers that are written in the 100GB plots. Then the transaction validation is done by whoever finds value in their storage (instead of doing a lot of computations online, they are pre-generated). I assume there's a bunch of tree-like structures in the middle to make the search faster.