A running total tells you how much has piled up, while a rate of change shows...
https://sticky-wiki.win/index.php/How_Do_I_Tell_If_a_Number_Is_a_Total_or_a_Rate_in_a_Report%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.