Google Mobile Services (GMS) is a collection of applications and application programming interfaces (APIs) developed by Google for manufactures of Android devices. The GMS services enable your android phones and tablets to work on par with Google to provide the best user experience.
Think of APIs as shortcuts for app developers to access device-level functionality. For example, casting a video to your TV over Wi-Fi or communicating with Google’s high-accuracy location services.
GMS can only be implemented into devices once the manufacturer has obtained a license from Google. Which then enables them to use the set of cloud-based applications. By placing all popular Google applications under one offering, GMS provides end-users with secure and consistent functionality.
Learning about Google Mobile Services (GMS)
Examples of popular applications within the GMS ecosystem include Google Play Store. The Android app store, Chrome, Google’s web browser, and Google Search.
Phone manufacturers have the option of pre-installing specific GMS applications, like Gmail or Youtube, on a device home page or offering them for download through an app store. Additional GMS applications include Google Drive, Hangouts, Maps, Photos, and Music.
Google Mobile Services extends this basic functionality to include deep system integration for things like workout detection through onboard sensors, access to payment services like Google Pay, and cloud saves through Play Games, among others.
The GMS service may vary based on country availability and licensing requirements. And it should not be confused with the Android Open Source Project (AOSP).
While the (AOSP) provides common, device-level functionalities such as email and call. GMS is not part of AOSP. GMS is only available through a license with Google.
So in layman’s terms, the open-source component of Android is the Android Open Source Project (AOSP). GMS, on the other hand, lives on top of AOSP and provides much of the nice-to-have functionality you may have come to expect from modern-day Android.
The key distinction between the two, however, is that GMS is not open-source. Instead, Google selectively licenses it to device manufacturers or OEMs for free.