DOM - Hierarchy

> (World Wide) Web - (W3|WWW) > The Document Object Model W3C API Interface (DOM)

1 - About

The nodes in the node tree have a hierarchical relationship to each other.

Merge with DOM - (Node) Tree

3 - Definition

3.1 - Precedence

An element A is said to be preceded or followed by a second element B if A and B have the same parent node and there are no other element nodes or Text nodes (other than inter-element whitespace) between them.

3.2 - Only Child

A node is the only child of an element if that element contains no other nodes other than:


4 - Terms

The terms parent, child, and sibling are used to describe the relationships. Parent nodes have children. Children on the same level are called siblings (brothers or sisters).

  • In a node tree, the top node is called the root. In HTML, it's the html element
  • Every node, except the root, has exactly one parent node
  • A node can have any number of children
  • A leaf is a node with no children
  • Siblings are nodes with the same parent