In iOS 12, a new Auto Update feature was introduced, which allows your device to automatically install new software versions as soon as they become available.
How to enable Auto Update in iOS 12
The new feature is located in Settings → General → Software update → Auto update. When you turn it on, your device will automatically install all available software updates.
It is not yet known whether the updates will be installed in the background, or the user still has to confirm the installation himself. As a reminder, previously Apple required different agreements to be accepted before installing each update iOS.
A new switch in Settings will be available on every supported iPhone, iPad and iPod touch.
The function has nothing to do with auto-update applications, which has been available for many years in the settings of iTunes and App Store.
In iOS, when a new version is released, an update screen appears in Settings. Users iOS 12 will still be able to manually manage the software update and install it instantly or set a timer for night time.
macOS has supported automatic updates for some time now, not only for core software, but also for security updates, system files, and more.
Auto-update: pros and cons
By default, the function is disabled, which is even good.
Users who always install new versions of the system without hesitation will probably want to enable the feature to always stay on the latest version available. But there are those who first read the postscript to the update, and only then decide whether to install it. Such users will choose not to use the feature.
Given the fact that early versions of major updates always contain bugs, it can be assumed that you will hardly be happy to wake up one morning and find a newly updated smartphone with many problems and errors.
It is up to you to decide whether to enable the function or not. Perhaps in the future Apple will leave it as the only default option, so that more smartphones will work on new versions for statistics.