What is the open-source Android codebase commonly abbreviated as AOSP?

AOSP stands for Android Open Source Project.

AOSP is the publicly available open-source codebase at the core of Android. Google leads its development and publishes the platform’s source code, including major operating-system components, framework code, system libraries, and tools used to build Android-based devices.

AOSP is not exactly the same as the software experience on most commercially sold Android phones. Manufacturers commonly modify the code for their hardware and add proprietary components. Google’s Android releases may also include closed-source Google Mobile Services, such as Google Play Services and the Play Store, which are separate from the open-source AOSP base.

The project’s history goes back to Android’s 2007 public unveiling. Its open-source licensing allows companies and communities to adapt Android, which has led to customized systems such as Samsung’s software layer, Amazon’s Fire OS, and community projects including LineageOS. The acronym refers specifically to the project and codebase, not to an app store or device-management service.