What do pivotX and pivotY mean in Android animations? [closed]

These two terms occur in many places but what exactly do they mean in the context of Android animations?

The pivotX and pivotY is the central point of the animation.
So for example if you want to do Zoom In animation you can use this

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:fillAfter="true" >

    <scale
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:duration="1000"
        android:fromXScale="1"
        android:fromYScale="1"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="3"
        android:toYScale="3" >
    </scale>

</set>

and the android:pivotX="50%" and android:pivotY="50%" will mean the zoom will be started from the center.

There is also a nice tutorial by android hive here