iPhone’s Advanced Sensors
iPhone employs advanced built-in sensors—an accelerometer, a proximity sensor and an ambient light sensor—that automatically enhance the user experience and extend battery life. iPhone’s built-in accelerometer detects when the user has rotated the device from portrait to landscape, then automatically changes the contents of the display accordingly, with users immediately seeing the entire width of a web page, or a photo in its proper landscape aspect ratio.

iPhone’s built-in proximity sensor detects when you lift iPhone to your ear and immediately turns off the display to save power and prevent inadvertent touches until iPhone is moved away. iPhone’s built-in ambient light sensor automatically adjusts the display’s brightness to the appropriate level for the current ambient light, thereby enhancing the user experience and saving power at the same time.