Android - Overview

Updated: 2019-06-27

The 3 "Layers"

If you want to be an Android developer, these are the 3 "layers" you need to be aware of.

Android Framework (Base)

AndroidX (JetPack):

Google Play Services (GMS)

  • packages under com.google.android.gms.*
  • Closed Source. Only Google certified companies can use it. When the news of "Google banning Huawei" came, it referred to this part, as Android(AOSP) is fully open sourced.
  • for both Google's 1st party apps(e.g. YouTube, Google Maps) and 3rd party APIs.
  • not available in China.
  • Some devices may use AOSP but develop their own GMS equivalents(e.g. Amazon Fire)

Other Notable Components

Besides platform/frameworks/base and platform/frameworks/support, here lists some other interesting/important repos:

  • platform/libcore: Google's implementation of some core Java libs(e.g. java.net, java.util, etc)