Sometimes when you turn your iPhone or iPod, the screen doesn’t move. In most cases, that’s because you’ve got the screen rotation turned off. This setting prevents your device from reorienting it’s screen no matter how you turn it. To check if screen rotation is turned off, look at the top right corner of the screen, next to the battery metter, for an icon that looks like a curved arrow surrounding a lock. If you see that, rotation lock is turned on.
To turn it on or off, follow this steps:
1. In iOS 7 or higher, swipe up from the bottom of the screen to open the Control Center. (In iOS 6 or lower, double tap the home button on the front of the iDevice. This will reveal the fast app switcher row of apps at the bottom of the screen)
2. In iOS 7 tap the “lock and curved arrow icon”. If it is white it’s on; black it’s off. (In iOS 6 or earlier, swipe left to right to reveal the Music app, music player controls, and on the far left, an app with a curved arrow in it (if the lock is turned on, you’ll see the lock inside the arrow) to turn screen rotation lock ON, tap the curved arrow icon so that the lock appears, to turn it OFF tap the icon so that the lockdisappears).