What is all the abbreviations?

Question

everyone speaks about these tiers and OO´s and OU´s and UU and everything like that. I dont understand anything. could you please make a list of all the abbreviations?

Answer 1

These are all competitive battling tiers.

You can check them all here.
There are a lot more types of battle tiers, but those are mostly the main ones.
Note, I know nothing about competitive battling, so please don't ask me about it. xD

Hope I helped. :)