What is the difference between android:icon and android:roundIcon

[Duc Ta]

Dear everyone,
When I try to change android app icon, i open AndroidManifest.xml and replace the default icon by the icon I want to change
I have seen that default icon is placed in 2 line of <application> tag

android:icon 
android:roundIcon

And I do not know what is the difference between android:icon and android:roundIcon
Can anyone explain it to me?

Thanks and best regards!

[Pete Letkeman]

I did find this:

Android 7.1 Notes wrote:Apps can now define circular launcher icons, which are used on devices that support them. When a launcher requests an app icon, the framework returns either android:icon or android:roundIcon, depending on the device build configuration. Because of this, apps should make sure to define both android:icon and android:roundIcon resources when responding to launcher intents. You can use Image Asset Studio to design round icons.

You should make sure to test your app on devices that support the new circular icons, to see how your circular app icons look and how they are displayed. One way to test your resources is to run the Android emulator and use a Google APIs Emulator System targeting API level 25. You can also test your icons by installing your app on a Google Pixel device.

https://developer.android.com/about/versions/nougat/android-7.1.html

But not too much else.  Maybe this is enough for you?

This page talks about icons as well
https://developer.android.com/guide/practices/ui_guidelines/icon_design_adaptive.html