Technology Fundamentals

Tree

Definition

A tree is a widely used abstract data type that simulates a hierarchical tree structure, with a root value and subtrees of children with a parent node, represented as a set of linked nodes.

Why It Matters

Trees are used to represent hierarchical data, such as file systems on a computer, the structure of an XML or HTML document (the DOM), or company organizational charts. They enable efficient searching and sorting of data.

Contextual Example

A file system is a tree. The root directory is the root of the tree, and each folder is a node that can contain other folders (branches) or files (leaves).

Common Misunderstandings

  • A Binary Search Tree (BST) is a specific type of tree where each node has at most two children, and it's kept in a sorted order, which allows for very fast searching.
  • Unlike a real tree, in computer science, a tree is usually drawn with the root at the top.

Related Terms

Last Updated: December 17, 2025