What does it mean when an App in the Dock shows a number in the upper right of the App icon?

I have an iMac that was purchased last year and I am learning the nuances of the High Sierra OS. On my iMac, Reminders and Calendar both have numbers in the upper right of their respective App icons? What actually does this mean? I assume they indicate the number of events pending for that particular day, but correct me if I am in error. When I launch ether App, there is nothing listed. I do not know how to remove the numbers. I have read numerous High Sierra Resource Books and other than explaining what the App is, there is no mention of the little red dot with a number inserted or its meaning, unless there is an Apple Doc which describes its purpose.

Any help would be appreciated