A running total adds up what has come in, while a rate shows how fast it comes...

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

A running total adds up what has come in, while a rate shows how fast it comes in. Use parcel counts to see why 20 parcels by noon differs from 5 parcels per hour, and why units and time windows matter when you read a work chart.