Hi Ruthie, Stippling is a type of quilting where you drop the feed dogs and stitch a continuous curvy line of stitching that never crosses over itself. There are no corners and the space between lines is about 1/4" or less. If it's much larger than that, it's called meandering. If you go to the following link, it will show you a demonstration.
http://www.taunton.com/Threads/pages/tvt035.asp