A running total tells you how many parcels have arrived so far, while a rate of...

https://www.bright-bookmarks.win/a-running-total-shows-how-much-has-accumulated-while-a-rate-of-change-tells

A running total tells you how many parcels have arrived so far, while a rate of change shows how many arrive per hour. This article explains how units and time windows help you tell those numbers apart and use them with confidence.