What are nodes that do not have any children called?

Nodes that do not have any children are referred to as leaf nodes. In the context of tree data structures, a leaf node is situated at the end of a branch and represents a terminal point where no further subdivisions occur. The defining characteristic of a leaf node is its lack of child nodes. This concept is crucial when traversing or manipulating tree structures, as operations often involve identifying and processing these terminal nodes.

Other types of nodes serve different purposes within a tree structure. Root nodes are the topmost nodes that serve as the starting point of the tree. Internal nodes, on the other hand, have at least one child, functioning as intermediary points that connect leaf nodes to the root. Branch nodes, while less commonly defined in standard terminology, typically refer to nodes having child nodes but do not specifically indicate whether they serve as the terminal points like leaf nodes do. Understanding these distinctions helps clarify the role each type of node plays in tree data structures.