title: What does @dimen/activity_vertical_margin do?
body: <p>In the following code:</p>
  
  <pre><code>&lt;LinearLayout
      android:id="@+id/activity_main"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      android:orientation="vertical"
      tools:context="com.example.android.ashokaquiz.MainActivity"&gt;
  </code></pre>
  
  <p>What does <code>@dimen/activity_vertical_margin</code> do? I cannot find any documentation for it. I know what padding is. I just want to know about the <code>@dimen/activity_vertical_margin</code> bit.</p>
  
  <p>Thank you.</p>