Why Location services is Part of the Google Play service APK?

Question

I know Location Services is part of the Google Play services APK.

I have gone through the below link regarding the Location Update.

http://developer.android.com/training/location/receive-location-updates.html#PlayServices

I need the following things to be clarified to work the Google Play Services - Location Update or User Activity Recognition.

o   Why the Google play store needs to be installed to get the location update or user activity status. 
o   Why the required functionality is not integrated with android SDK. 

Please help me on this.

Answer 1

You can also check this link, Overview of Google Play Services

Q1. Why the Google play store needs to be installed to get the location update or user activity status.

Google Play services APK contains the individual Google services and runs as a background service in the Android OS. You interact with the background service through the client library and the service carries out the actions on your behalf.

Q2.Why the required functionality is not integrated with android SDK.

Google Play services gives you the freedom to use the newest APIs for popular Google services without worrying about device support. Updates to Google Play services are distributed automatically by the Google Play Store and new versions of the client library are delivered through the Android SDK Manager. This makes it easy for you to focus on what's important: your users' experience.