From Nookipedia, the Animal Crossing wiki.
 Types of DS
There are four different versions of the Nintendo DS, all with bottom touch screens.
 Classic Nintendo DS
The first model of the DS is commonly called the DS Phat due to its bulkier appearance. It was released November 21, 2004 in North America, December 2, 2004 in Japan, February 24, 2005 in Australia, and March 11, 2005 in Europe.
 Nintendo DS Lite
The second model was known as the DS Lite and was known for its slimmer body and a brighter screen. More DS Lite consoles have been sold than any other DS model so far.
 Nintendo DSi
The Nintendo DSi introduced many new features such as two cameras and matte surface to produce less fingerprints. It also introduced apps that you can download from the Nintendo DSi Shop.
 Nintendo DSi XL
The last model developed was the Nintendo DSi XL. It is 93% the screen size of the original DSi. The DSi XL was released in Japan in late 2009, in early March in Europe, and on March 28, 2010 in North America.
The Stylus is a utensil that is used to operate the lower screen on the Nintendo DS (commonly called the touch screen). The Nintendo DSi XL has two different sized styluses, one full sized, and the other slightly bigger than the Nintendo DSi's stylus. Animal Crossing: Wild World has two different control schemes: one that is entirely controlled by the buttons on the DS, and one that is controlled entirely by the stylus. Input from the method not currently in use will cause Wild World to switch control modes; however the initial input will not be recognized until used again.
Playable Animal Crossing games:
By DSi Ware: