a obw you line up layers of fabric so the design is exactly in the same space and cut your shapes in the same place through the layers...fussing cutting you take a piece of fabric with designs (like roses) and you use a pair of scissors and cut out that rose.,..or what ever, maybe a car or a tree.... you carefully cut out individual shapes from the fabric, so when you are done your piece of fabric looks like swiss cheese...obw fab's are cut in strips, and the pieces are cut all at once...no waste.