The features of the iPhone 3GS primarily consist of faster performance, a higher resolution for the camera, which now supports video recording, voice control, and support for 7.2 Mbits/s HSDPA downloading, altough the uploading has been unchanged ( 384 kbps) because of Apple not implementing the HSUPA protocol on this version of the iPhone. The iPhone was not available for all countries at the same time, as U.S., Canada and six other European countries benefited of the release of the iPhone 3GS on June 19,2009, while Japan and Australia got to the the device on the store's shelves starting with June 26 of the same year. The international release of the third generation iPhone took place in July and August 2009.
The iPhone 3GS runs Apple's iOS (first called iPhone OS) operating system, which combines original elements with some borrowed from the Mac OS X operating system, which is also developed by Apple, but intended for Machintosh based computers. Apple's iOS is present in all its touch screen based devices, from all other iPhone models to the iPod Touch portable media player and the Apple iPad tablet computer. The applications intended for the iPhone are called Apps and it is highly recommended that they are first approved by Apple itself and obtained through the company's online store, called the AppStore. Doing otherwise could lead to serious damage of the device's software which cannot be covered by the product's warranty.
Since it uses the iOS operating system, it is obviously that the iPhone 3GS resembles other iPhone models and is controlled by a multi touch screen based LCD display. The 3.5 inch liquid crystal display is intended for bare finger usage, and since it supports multi touch, several fingers can be used for actions that require it, like games or zooming in and out of a web page. Normal styluses and gloves won't work with the iPhone 3GS (neither iPhone version, for that matter) because it is not capable of producing the required quantity of electrical conductivity, needed by the device's capacitive screen. However, there are special gloves and styluses specially intended for this purpose. Most upgrades from the previous model regard hardware speed and performance, as the phone's name suggests (the "S" in "iPhone 3GS" stands for "speed" ).
Although most improvements seek hardware speed, there are some software features that were introduced to the iPhone world by the iPhone 3GS. However, these features were then implemented and even improved in the iPhone 4. Since the release of the iPhone 4, the respective features were no longer exclusive for the iPhone 3GS.