What does @dimen/activity_vertical_margin do?
<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>