The Advanced Photo System, or APS for short, was designed by Canon, Kodak, Fuji, Minolta and Nikon with the consumer in mind.   Its ease-of-use, outstanding print quality, and long list of features are described in the links that follow.

Fuji -- a large section about APS cameras and film.

Kodak -- a section devoted to explaining APS technology to beginners and to selling their Advantix products.

Kodak -- this page is more advanced.  It explains the history and technology behind APS.

Minolta -- describes the benefits of APS.

Agfa -- A good, well-illustrated overview of APS technology.

Photo Magazine -- Decent explanation of APS.