A running total shows what has built up. A rate shows how fast it changes. With...

https://activecalculus.org/author/Running-Totals-Rates-of-Change

A running total shows what has built up. A rate shows how fast it changes. With parcel counts and rainfall, this article explains units and time windows, like parcels per hour or rain in a day, so you can read a chart without mixing the two.