Can someone explain the diffrence between straight, right, and left. I know that right, and left refers to the direction the feathers go from nock to tip, and the "wing" of the feathre based on the base of the feather. Is there anything else, and what is the purpose of strait?

Also, is the hellical adjustable on the Bitz jig. ie can I make the feathers more strait, but still at an anlge down the arrow, or do they have to be radically curved.
Sorry for the bad descriptions. Does anyone know of a book that would help as well?