A running total tracks parcels delivered so far, while a rate of change shows...

https://www.foxtrot-bookmarks.win/see-how-a-running-total-of-parcels-differs-from-a-rate-of-change-one-tells-how

A running total tracks parcels delivered so far, while a rate of change shows how quickly deliveries are happening. This article explains the difference, why units matter, and how a time window like per hour or per day can change the story.