Running totals and rates of change answer different questions: how much has...

https://spark-wiki.win/index.php/How_Do_I_Explain_the_Difference_Between_Account_Balance_and_Cumulative_Deposits%3F

Running totals and rates of change answer different questions: how much has accumulated, and how quickly is it changing? See how parcel counts over a shift or rainfall in an hour clarify the difference, with units and time windows in view.