31. Introduction to Trees (Terminology, Root, Nodes)

A Tree is a non-linear hierarchical data structure consisting of nodes connected by edges, mimicking an upside-down tree.

Key Terminology

Root: The topmost node of the tree. A tree can have only one root.
Node: The fundamental unit containing data and references/pointers to other nodes.
Edge: The link connecting two nodes.
Parent: A node immediately above another node.
Child: A node immediately below another node.
Leaf: A node that has no children.
Depth: The length of the path from the root to a specific node.
Height: The length of the longest path from the root to any leaf node.

We will focus primarily on Binary Trees, where every node can have at most two children: a left child and a right child.