## What is a tree ?

A general tree is a tree where each node may have zero or more children. Tree is a non-linear data structure which organizes data in hierarchical structure.

Every element is called a Node. Node stores data of that element and link to other element in hierarchical structure.

## Tree Terminology

### Root

In a tree data structure, the first node is called as Root Node. It is the origin of the data structure. Every tree must have root node.

### Edge

The connecting link between any two nodes is called as Edge.

### Parent

The node which is predecessor of any node is called as Parent node.

### Child

The node which is descendent of any node is called as Child node.

### Leaf

The node which does not have a child is called as Leaf node.

### Internal nodes

The node which has at least one node is called as Internal node.

### Sub tree

Sub tree represents the descendants of a node. Each child from a node forms a subtree recursively.

### Examples

File systems, family tree etc

**Figure :** Tree for File System

**Next >**