1, n2, ‚Ä¶, nk such that ni is parent of ni+1 for 1 ‚â§ i ‚â§ k</p></li>
<li><p>Length: number of edges in the path</p></li>
<li><p>Internal path length: sum of the depths of all the nodes</p></li>
</ul>
</li>
<li><p>Binary Tree - every node has at most 2 children</p></li>
<li><p>Binary Search Tree - Each node has a key value that can be compared</p>
<ul>
<li><p>Every node in left subtree has a key whose value is less than the root‚Äôs key value</p></li>
<li><p>Every node in right subtree ha