Before we walk through how the tree data structure can be utilized to manage data, there are some key terminologies you should become familiar with. This guide walks through each of these terms. These examples all use a binary search tree, however many of the concepts, such as nodes and edges can be applied to all trees and graphs.

Root

Definition: The very top node of a tree.

Child

Definition: Any node connected to another node, while moving away from the root node.

Parent

Definition: A node that contains child nodes

Siblings

Definition: Multiple nodes connected to the same parent node.

Leaf

Definition: A node with no child nodes.

Edge

Definition: Connection between one node to another node.

Path

Definition: A sequence of nodes connecting a node with a descendant node.

Tree Height

Definition: Number of edges in the longest path from the root to the leaf node.

Depth

Definition: Number of edges from a node to the tree's root node.

Summary

Now that you have a good idea of the key terms associated with trees you're ready to start walking through each of the key structures and how they can be used.