I know that a summary activity includes all activities below it and it's everything is calculated automatically according to activities below it.
I also know what high level means.
But I am confused if we should call a summary activity also a high level activity or they are different? What is a summary activity vs a high level activity? What differences are there between them?
Let's say you have a subnet of 10 activities under a summary activity. Well, if you want to make a high level activity of these 10 activities, again wouldn't it be equal to a summary acitivity or what am I missing?