Google Play services is an app that runs in the background on mobile devices running the Android Operating System (OS) 2.2 and later. Play services provides developers with a library of application programming interfaces (APIs), which are used to provide Android apps with core functionalities such as authentication services, privacy services, location services and push notification services.
The Google Play APK (Android application package) is installed by default on most Android devices and if Google Play services is de-activated on the client-side, it is very likely that apps on the mobile device will not work properly. To protect user privacy, some services -- including location awareness -- require the end user to authorize (allow) the service before it will run.
Google Play services has two important security features, Verify Apps and SafetyNet. Verify Apps is a cloud-based service that scans applications for malicious code before users install them, whether the app is acquired from the Google Play Store or by sideloading, and flags any potentially harmful applications. Verify Apps can also remove or disable an application without the user's confirmation. SafetyNet assesses whether the device has a security model consistent with Google's Android security requirements, compiles data about possible malware threats and attacks, and updates application blacklists and settings on the device to prevent these attacks.
Google Play service updates apps through the Google Play store. The updates are done independently of Android Operating System or carrier updates to ensure timeliness and a better user experience across fragmented Android device operating systems.