Imagine you have 50 drawers in your tool trailer.
If you tell a helper to get a screwdriver from the drawer labeled "Screwdrivers", he needs to look at every drawer label until he finds the "Screwdrivers" drawer.
Instead, if you tell him to get a screwdriver out of drawer #37, he can quickly find drawer #37 without looking at every drawer.
Numbers reference each other, but labels with drawers contents don't.
Numbers tell you where a drawer is.
Content labels tell you what's in it.
