From AOSP docs:
> Android is intentionally and explicitly an open source effort (as opposed to free software)
https://source.android.com/docs/setup/about
One of the reasons Android was a success while Windows Phone failed, Microsoft charged something like $30 per device for the OS license.
From AOSP docs:
> Android is intentionally and explicitly an open source effort (as opposed to free software)
https://source.android.com/docs/setup/about