Do you mean "ride categories?"?
Those are a way to divide up your rides - primarily for those using filters - so you can split out one type of ride vs. another. So you can answer the questions:
How many commutes did I do this year?
How many group rides did I do?
How did my races improve or not over the season?
How many miles do I have on the road, vs. the in the woods? (oh, no...wait...you still can't answer that one)
How many miles do I have on Bike A, vs. Bike B. (oops...nope...can't answer that one, either)
Personally, I don't think they are all that great. I don't like that I can't answer those last 2 questions (at least...I haven't figured out how) Also, does 2 people on a ride make a "group"? Is my weekly ride with the folks at the shop a "general"/"leisure" ride...cuz it sure is fun, or is it "training"/"general"? If I do an organized ride with those same folks, is that an "event" or is it a "club" ride?
And...if I don't set my own standards for answering those questions...or worse, if I apply what little standards I have
inconsistently, then my filters get all messed up.
(Geez...can you tell I fret about those things....a lot??)