Default padding in layout created by Eclipse

Question

When creating a blank Android project in Eclipse, the newly created "Hello World" layout has a built in padding like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin" >

I couldn't find anything in Google design guidelines, also Google's own apps don't have such a padding. But I thought there has to be a reason why it is there. Any ideas?

Answer 1

This is from Android guidelines, see here.