With every iOS version, Apple introduces new features and improvements. Thus you may want to upgrade your device’s iOS version. Here is how:
1-Ensure that you have the latest version of iTunes.
2-Connect your device to your computer.
3-Select your device in iTunes under Devices.
4-Click “Check for Update”
5-If there is an update, iTunes will prompt you to download the update, then click “Download and Update”.
You may also upgrade your iOS wirelessly if your device is using iOS 5 or later. To do this; simply tap Settings > General > Software Update.