Tracy, using a spool or a cone is a personal preference, but in the cone you get much more thread. Most spools are filled in such a way that the thread has to be pulled from the side, on the regular thread dispenser of the machine. Cones are too big and can not be placed on the machine, and that's when you use whatever attachment you have next to the machine. Also they are filled differently. I personally prefer cones, because I sew a lot and hate it when the spool finishes. If only I could use something that size on my bobbin I would be set for life.