Kits refer to prepackaged kits with both a pattern and a fabric packet. The fabric may or may not be precut to some extent, but all of the design decisions were made by the kit maker, and the quilt maker provided only craftsmanship to assemble the kit.
Adaptations refer to quilts made from an existing pattern or plan, whether purchased, published in a book or magazine, or just an existing pattern (Log Cabin, SunBonnet Sue, etc.). The quilter is making fabric, color, and value decisions, but the pattern is not original.
Original Design refers to a quilt that is totally original, both in the pattern and the color choices. NOTHING in the quilt is derived from anyone else's work. Original Design work is very rare.