Google Play Services
If you've ever explored the list of installed applications on your Android device, you've likely come across Google Play Services. You'll also find a grey application in the tray called “Google Settings,” which corresponds to the Play Services application.
The Google Play Services application is a single place to bring all of Google's APIs on devices running Android 2.2 and higher. These APIs, or Application Program Interfaces, are used by app developers as a means to access many of Android's core features. In other words, Google Play Services makes it easier to get your smartphone to do, well, smart things.
The killer feature with Google pushing Play Services onto a device is that it unlocks these features without waiting for an upgrade to the operating system.
In the last twelve months, following the introduction of Android 4.3, we've seen features such as single sign on, cross-device notifications, geofencing, activity recognition and significant improvements to push notifications. Older devices running Android 2.2 and later have benefited from these improvements without needing an upgrade to the operating system because Google Play Services handles these services.
We have already seen the applications separated from the operating system for some years now, but it is becoming more and more widespread. Google, HTC and Motorola already provide updates to their suite of applications via the Google Play Store including Gmail, Chrome, BlinkFeed and Moto Assist.
This gives users the advantage of being able to access the latest version of a given application without waiting around for an Operating System update, which in some cases will never arrive. A good example is my aging Dell Streak, which runs Android 2.2 and of course has the new Google Play Services application pushed to it with regular updates.