What Is a Period?

When I went to school, it's probably changed since then the way we used to classify Secondary school was to talk about different forms. So first form your first year first form second third fourth fifth and then Confusingly the last two years instead of calling them sixth and seventh they call them lower sixth and Upper sixth so whatever form you were in you were a former. Now when you have a break go out and play football play games in The playground the area where you're allowed to play now if I spoke to you Craig of A period but at school or maybe even a double period.