The Apple iPhone is a mobile phone, music and movie player, game console and mobile Internet device that runs on the iOS operating system. Due to the complexity of this device, occasionally issues pop up that cause the iPhone to either lock up or function incorrectly. Shut down or reboot your iPhone to resolve these issues.
Shut down your iPhone by holding down the power button for up to 10 seconds. The power button is a hardware button located on the top-right edge of the phone.
Slide the red slider bar that appears on the screen next to "slide to power off" to the right to turn the iPhone off. To power the phone back on, press and hold the power button for a couple of seconds. A white Apple logo appears on the screen while the phone is starting up.
Reboot the iPhone in the case of a freeze or lockup; hold both the power button and the home button down simultaneously for approximately 10 seconds. The iPhone screen goes blank and then starts booting back up.