Cleo - Standard deviation is just a way to characterize whether a set of data points, like CGM glucose data, is tightly packed close to the average or more widely dispersed. A tightly packed set of data points equates to a low standard deviation whereas a more dispersed set of data points will yield a higher SD.
I found this animation that visualizes it well.
I never took a college class in statistics and learned this concept solely from watching my CGM reports.
Is a DBE a diabetes educator?
Terry