Good question! I’m on Mojave <https://help.apple.com/assets/5BFDD3F8094622802EEE504F/5BFDD...> and if I had to guess the categories would be:

User interface/desktop

peripherals/hardware

networking/connectivity

organisation (very specific, I know)

Security doesn’t really fit into the first one

While they can make kind of sense it doesn’t really help me as a user.