The iPhone has three orientations, portrait, landscape right and landscape left. Photo browsing, Web browsing or playing music, support portrait mode, as well as landscape(both left and right). Unlike the iPad (a tablet computer launched in 2010 by Apple which is very similar to the iPhone and iPod, but larger), the iPhone's display does not change when held upside down (with the home screen above the display). Apple launched a 3.0 update to its iOS (first called iPhone OS) which enables support for different viewing modes to different applications, such as mail.
The 3-axis accelerometer sensor is also used for applications, such a games. Apple made available on the iPhone 4 a gyroscopic sensor as well, which enhances the perception of the device on how it is being moved. In 2008, Apple launched a software update which allowed the first iPhone model to use cell tower and Wi-Fi network locations trilateration, despite the device lacking GPS hardware. The second, third and fourth generations of the iPhone (the iPhone 3G, the iPhone 3GS and the iPhone 4 respectively) are equipped with A-GPS. The iPhone 3GS and iPhone 4 also have a digital compass implemented. The iPhone features an internal rechargeable battery, which is similar to the one in the iPod, because it is not user-replaceable. This battery can be recharged by connecting the iPhone to a computer for sync.
With the included USB cable, or you can add the AC power adapter (also included when buying the iPhone) to the USB cable and charge the device directly from an AC outlet, or perform "wall charge". Apple made several accessories regarding battery recharging available for the iPhone, including car recharger or even solar chargers. Some other accessories are available, like stereos.
After running test on pre-production models, Apple stated on their website that the iPhone's battery was designed to retain 80% of its original capacity after 400 full charge and discharge cycles. The original iPhone's battery was said to resist through 7 hours of video, 8 hours of talking, 24 hours of music and up to 250 hours on standby (which is similar to the iPod's battery). The current most efficient battery used by an Apple product is that of the Apple iPad which can hold up to one month in standby, 10 hours of video and over 100 hours of music.