title: What is the meaning of android:orientation attribute in xml file as part of ConstraintLayout
body: <p>I'm trying  to understand what is the meaning of <strong>android:orientation</strong> attribute in layout xml file as part of ConstraintLayout
  In The code:</p>
  <pre><code> &lt;androidx.constraintlayout.widget.ConstraintLayout
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;150dp&quot;
          app:layout_constraintTop_toTopOf=&quot;parent&quot;
          app:layout_constraintStart_toStartOf=&quot;parent&quot;
          android:orientation=&quot;horizontal&quot;
  </code></pre>
  <p>As far as I know, each valid attribute as a &quot;meaning&quot; but when changing between <em>horizontal</em> and <em>vertical</em> values nothing really change.
  Don't I understand correctly the meaning  of orientation or my assumption that each attribute as a meaning is incorrect?</p>