A running total tells you how much has piled up, while a rate of change shows...

https://wiki-wire.win/index.php/Why_Does_Calculus_Care_Whether_Change_Is_Discrete_or_Continuous%3F

A running total tells you how much has piled up, while a rate of change shows how fast it’s growing. With parcel counts or rainfall, the article explains why units matter and how a daily rate differs from a weekly total over the same span.