In short, nothing. A "presentation" ends with the .ppt extension and
will generally open in Normal/Edit View when double-clicked. A "show'
ends in a .pps extension, and will generally open in Slide Show View when
double-clicked. The files themselves are identical, and you can always
open a "show" in Normal/Edit View by either changing the extension to
..ppt or opening PowerPoint first and opening the presentation by choosing
Open from the File menu.
--David
--
David M. Marcovitz, Ph.D.
Director of Graduate Programs in Educational Technology
Loyola College in Maryland
Author of _Powerful PowerPoint for Educators_
http://www.loyola.edu/education/PowerfulPowerPoint/