Every Android device needs Google Play Services to update the Google applications and applications from the Google Play. This proprietary background service and API package was introduced in 2012 and now it provides access to many Google services (Google+, Maps, Location APIs etc) and allows applications to communicate with the services through common means (GMS).
The users will install the Google Play services APK to have access to Google’s services, and they won’t need to worry about it, because it will run as a background service in your Android OS, without bothering you. The interaction with it will be made through the client library and the service will perform actions on your behalf.
The new versions of the Google Play services can be downloaded through the Google Play Store, but you can also get them from third party sources such as androidapksfree, and the services don’t depend on your carrier or OEM system image updates. If your device is running on at least version Android 2.3 (API level 9) and you’ve already installed Google Play services on it, you will be getting updates within a few days. If you’re running older versions than Lollipop 5.0, you will download APK files with version number starting with “O” after the dash. The version 7.5.73 (1976294-440) has a file size of 43.8MB and was released a few days ago, containing bug fixes and other improvements.
The latest stable version that can be downloaded from the Google Play store is 7.3 and it brought: Maps API v2 for Android Wear, Wear API improvements, Fit API improvements, Location API improvements and Places API improvements.
Here are some of the tools included into the Google Services:
Google Play Game Services – the app developers allow the gamers to use leaderboards, public or between friends, to share their achievements etc.
Location APIs – include Geofencing APIs to schedule specific actions when the user enters or leaves certain geographic boundaries; and Fused Location Provider which acquires location information without using too much power when the applications adapt to the current action of the user.
Google+ allows the users to be automatically authenticated inside applications.
Maps – allows applications to use Google Maps or Street View without opening a separate app.
Drive allows the users to store their documents on the cloud, to easily look for them and to edit them.