Congratulations! You are correct. A glider is similar to an airplane, but it has no engine. Instead it uses air currents or updrafts to stay in the air. Updrafts are strong upward air currents that allow the glider to gain height and to stay in the air for long periods of time.  Keep reading.

Image of glider from "Microsoft Office Online" <http://office.microsoft.com/clipart/default.aspx?lc=en-us&cag=1> (October-March, 2004-2005). Clip art available only to licensed users for non-commercial purposes.