I am not able to understand any of the questions because the jargon used is unfamiliar although the concepts look simple. Are all these terms specific to a particular framework ? Genuine question, thanks.
Then the GP goes into detail about a tree-like structure of categories and their parents. If you're not familiar with trees and graph algorithms this might be quite daunting.
Do some googling on the terms I mentioned and please ask about specific things you do not understand.
Minor correction: create, READ, update, delete