How many iterations of the DS have been released?
Nintendo DS family

The Nintendo DS Lite (abbreviated to DS Lite) is a dual-screen handheld game console developed and manufactured by Nintendo. It is a slimmer, brighter, and more lightweight redesign of the original Nintendo DS. It was announced on January 26, 2006, more than a month before its initial release in Japan on March 2, 2006 due to overwhelming demand for the original model. [3] It has been released in Australia, North America, Europe, New Zealand, Singapore, and defined regions in South America, the Middle East, and East Asia. As of December 31, 2013, shipments of the DS Lite have reached 93.86 million units worldwide, according to Nintendo. It was the final handheld to have backwards compatibility with Game Boy Advance games.[4]