When it comes to installing new i OS on i Phone i Pad i Pod touch, normally, there are two basic ways to make it.
One way is to downloadd and install i OS 9 OTA (Over the Air), and the other is using i Tunes.
Apple announced at the event that i OS 11 would be available in beta form to developers right away, with the public beta not too far behind.
Indeed, it became available to the public on 26 June 2017.
If you have limited space on your device or software update isn't working for whatever reason, you can update using i Tunes.
If you're running a the developer or public beta, Apple might push you an update if the build numbers are different (we're still checking on that).
It is always a good idea to take a backup of your device before updating it with the latest i OS software update.
(Note that if you choose to encrypt your backup using i Tunes, along with normal data, secure information like passwords etc.
If your device still doesn't have enough space, you can use i Tunes to update your device.
Update: Apple has released i OS 9.3.2 for bug fixes and security improvements.
So please install the latest i OS 9.3.2 software update instead of i OS 9.3.
The following devices are not supported on i OS 11: Original i Phone, i Phone 3G, i Phone 3GS, i Phone 4, i Phone 4S, i Phone 5, i Phone 5c, original i Pod touch, i Pod touch 2nd-gen, i Pod touch 3rd-gen, i Pod touch 4th-gen, i Pod touch 5th-gen, original i Pad. First sign up to the public beta, which will require you to input your Apple ID and agree to the terms and conditions.
You can then log in to the Beta Software Program, click Enroll your i OS device and follow the onscreen instructions.