photo stories: Semi-automatic shooting modes (part three)
Shutter priority (S) and Aperture priority (A) modes
S: In this mode you can set a specific shutter speed (fast to freeze action, or slow to blur objects). For example, with a faster shutter speed you can freeze the movement of the water. A: You can set a large aperture (smaller number) to throw a background out of focus, or set a small aperture (large number) to increase the depth of field. Sources used for this tech article:
The Practical Illustrated Encyclopedia of Digital Photography (Steve Luck, published by Hermes House)
