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

https://travissgreatthoughtss.swiftnestly.com/posts/what-units-do-i-get-when-i-integrate-a-rate-like-mm-per-hour

A running total tells you how many parcels have arrived so far, while a rate tells you how quickly they’re coming in. This article compares both, with clear units and time windows so the numbers make sense on a real shift.