de with no parent; there can only be one root</p></li>
<li><p>Leaf: a node with no children</p></li>
<li><p>Siblings: two nodes with the same parent</p></li>
<li><p>Height of a node: length of the longest path from that node to a leaf</p>
<ul>
<li><p>Thus, all leaves have height of zero</p></li>
<li><p>Height of a tree: maximum depth of a node in that tree = height of the root</p></li>
</ul>
</li>
<li><p>Depth of a node: length of the path from the root to that node</p></li>
<li><p>Path: sequence of nodes n