Running totals add up parcels or rain over time. Rates of change show how fast...

https://milosmasterdigest.cloudhinter.com/posts/what-does-em-a-b-a-a-em-over-em-b-a-em-actually-measure

Running totals add up parcels or rain over time. Rates of change show how fast they arrive or fall. This article sorts out the difference, names units like parcels per day and inches per hour, and shows how a clear time window helps you read a chart.