The iPhone 3GS (originally styled iPhone 3G S) is a smartphone that was designed and marketed by Apple Inc. It is the third generation iPhone, successor to the iPhone 3G. It was introduced on June 8, 2009, at the WWDC 2009 which took place at the Moscone Center, San Francisco.
This iPhone is named "3GS" where "S" stood for Speed. Improvements include performance, a 3-megapixel camera with higher resolution and video ability, voice control, and support for 7.2 Mbit/s HSDPA downloading (but remains limited to 384 kbps uploading as Apple had not implemented the HSUPA protocol). It was released in the U.S., Canada and six European countries on June 19, 2009, in Australia and Japan on June 26, and internationally in July and August 2009. More: en.wikipedia.org.