The public version of iOS 11 is coming on 20 September @ 1am (Singapore time). You can update your iOS devices via over-the-air (OTA) or via iTunes. As it is a major software update, the file size will be large and the updating process will take some time.
If you are in the rush, it is not recommended to update to iOS 11 as it will take a longer time than the other software updates process to complete, and also just in case if the update encounters any errors.
As always, do a backup to iCloud and/or iTunes before updating your software in a case that the software update fails and to avoid any data loss. You may also encounter battery drain during the first few hours of use and it is considered normal as the iOS would need to re-index, like unpacking and labelling your items in place.
While your device updates, so what is new in iOS 11?
In June 2017, Apple announced the next major update of iOS at this year’s WWDC, iOS 11. It comes with lots of new and changes to the design and features of iOS and the biggest leap for the iPad, making multitasking even better.
You can read on all of that changes here.
Here are the Changes and New Features in iOS 11: