Charlton,
Long cycle is a specific combination of two lifts: the clean, and the jerk. When you clean one or more kettlebells, then jerk, then drop to the rack and clean and jerk again, you are doing long cycle. If you clean the bell(s) and do multiple jerks, that's the short cycle jerk, or just jerks.
Long cycle= clean, jerk, clean, jerk, clean, jerk.....
Long cycle applies specifically to the clean and jerk. Other lifts are not long cycle. Long cycle is generally used to develop work capacity and full body explosive strength. It works the muscles that pull (clean) and the muscles that push (jerk), as well as core stability and cardio. Add in a full squat and some rotational stuff, and it may be all you need, in my opinion.
Hope this helps. I compete in long cycle, so I'd be glad to answer any questions. Others here have quite a bit of experience with this lift as well.