Ah okay thanks a ton! I think that clears it up. So basically:

- The idea is that every source/destination ("node") of funds keeps their own account for every node they deal with. And every transaction ("directed edge") necessarily needs to be tracked by both accounts in an equal and opposite manner.

- This is mainly only useful for businesses, as they generally have multiple sources of income (and/or multiple creditors) and need to be able to explain/track them. (At least as far I can see, I don't really see much of a point in doing this for the average person.)