Running totals show what has piled up. Rates of change show how fast it adds...

https://wiki-byte.win/index.php/What_Is_the_Difference_Between_an_Entry_and_a_Running_Total_in_a_Log%3F

Running totals show what has piled up. Rates of change show how fast it adds up. With parcels, 120 in a day is not the same as 10 per hour. This article explains how units and time windows shape what a chart tells you, in plain terms.