Originally AKC started out with Sporting and Non-Sporting. Your dog was one or the other. Then they started adding the other groups. What was left over, stayed in the non sporting. Some dogs got stuck in there because AKC says they no longer do what they were originally bred for, while many say, that can be said of quite a few breeds. UKC's groups are split a little differently than AKC and I think, a little more accurately.
AKC Groups are: UKC Groups are:
Non-Sporting Companion
Herding Herding
Terrier Terrier
Hound Scenthound
Toy Sighthound & Pariah
Working Guardian Dog
Sporting Gun Dog
Miscellaneous Northern Breeds