See how a running total of parcels differs from a rate of change: one tells how...

https://lunasinspiringinsight.novacrestiq.com/posts/what-is-accumulation-in-everyday-language

See how a running total of parcels differs from a rate of change: one tells how many have arrived so far, the other how many arrive per hour. The article uses clear units and time windows to make both numbers useful in a shift report.