Running totals show what has piled up, while rates show how fast it changes....

https://www.apu-bookmarks.win/see-how-a-running-total-differs-from-a-rate-of-change-using-parcel-deliveries

Running totals show what has piled up, while rates show how fast it changes. Use parcels and rainfall to see why units and time windows matter: parcels by noon differs from parcels per hour, just as daily inches differs from inches per hour