Motion paths may be paths on which slide objects animate, but for all other practical reasons, they are essentially just ordinary paths (or lines) that have curves, points, etc. If you are familiar with the drawing tools in PowerPoint (Line, Curve, Scribble, and Freeform) — or if you use a graphic illustration program like Adobe Illustrator or CorelDRAW, you know that paths can be either open or closed. A circle is a good example of a closed path, whereas a curve is an open path.
Learn about open and closed Motion paths in PowerPoint 2010 for Windows.

