When it comes to updating your iOS, there are two steps involved: downloading and installing. Downloading is the process of caching data so that the device doesn't have to retrieve it again. This is done invisibly, and clicking Install Now will start the downloaded installer and perform the rest of the task. Downloading something is just a file found on your computer, while installing it means opening it and making a program available for use.
The easiest way to download iOS is wirelessly, directly on the device. This is fast, efficient, and easy to do. Under Mobile Data, you can turn on automatic downloads, but make sure you have an appropriate mobile data allocation in your service plan. OneNote for iPhone can be downloaded from the iOS App Store and used on any iPhone or iPod touch compatible with iOS 12.0 or later.
OneNote for Android can be downloaded from the Google Play Store and used on any Android phone or tablet compatible with Android 5.0 or later. OneNote for iPad can be downloaded from the iOS App Store and used on any iPad compatible with iPadOS 12.0 or later. Software comes with an “installer” which is a special program that configures the files of that software in the correct way so that it works properly when you use it. Windows will install any pending updates that are available for OneNote for Windows 10 and other applications.