Also, bring various of new features on every update version of iOS on iPhone, iPad, and iPod Touch, Apple also provides fixes bugs, improving stability and performance of their operating system. However, it also just fixes the security flaws, to block the jailbreak community or hackers, to exploit on the latest iOS version and no longer possible to perform a jailbreak.
But you should know, every device has a limited time to receive iOS updates from Apple, and this does not mean that Apple ignores users. However, because of hardware limitations are not able to run a higher version. So the only way is to replace your old iOS device to a newer model.
You can update your iPhone, iPad, or iPod touch to iOS latest version by OTA (Over The Air) or via Wireless. However, if you can not see the update on your device, via on application settings menu. You can update manually using iTunes.
Updating the iOS version by OTA or Over The Air method. Updates will be directly on your device and do not require a computer or laptop, and you only need to connect your iPhone or iPad with WIFI network with a fast connection and stable, to download and install the iOS file.
Updating your device via OTA or wirelessly
Step 1: Plug the device to a power source, then connect to the Internet with Wi-Fi.
Step2: Next, tap on the Settings app> General and tap on the Software Updates section.
Step 3: on Software Updates section you need to tap on Download and Install button.
If you find a message asking for the application to will removed temporarily for iOS requires more space for the update to new version, tap Cancel. You can choose an alternative method for updating, by using iTunes or manually delete content from your device. Updates by using the iTunes application or update wirelessly, you will have space for the same amount in the device after updated.