My understanding is that both are open to a similar extent: the kernel is open-source; most of the rest of the system isn’t.
I don’t use or work on android so I could be wrong.
The only closed source stuff is device-specific hardware drivers.
Also, Android the platform is more open than iOS, you can build and install any APK you like and even root your device if you want. iOS restricts you to the app store.
IIRC only two major things aren't included: binary blob-only drivers, and proprietary Google apps: Play store, Maps, etc.
Despite those limitations, you can practically just `git clone` and build the entire OS for your device. :-)
https://source.android.com
My understanding is that both are open to a similar extent: the kernel is open-source; most of the rest of the system isn’t.
I don’t use or work on android so I could be wrong.