Now don't take me wrong but, I think everyone who is serious about quilting should learn all they can about fabrics and threads and how they are made. This info is invaluable. It will make your life as a quilter (seamstress or embroiderer) much happier and the quality of your work will show it. It is kinda like learning to use all of the feet that come with your sewing machine. Once you understand them, you will know without even thinking which to use and with what. In the mean time, take this good advice that Z gave you, learn your threads.