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HTML DOM Node Tree

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The HTML DOM views a HTML document as a node-tree.

All the nodes in a node tree have relationships to each other.


The HTML DOM Node Tree (Document Tree)

The HTML DOM views a HTML document as a tree-structure. The tree structure is called a node-tree.

All nodes can be accessed through the tree. Their contents can be modified or deleted, and new elements can be created.

The node tree below shows the set of nodes, and the connections between them. The tree starts at the root node and branches out to the text nodes at the lowest level of the tree:

DOM HTML tree


Node Parents, Children, and Siblings

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

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).

Look at the following HTML fragment:

<html>
  <head>
    <title>DOM Tutorial</title> 
  </head>
  <body> 
    <h1>DOM Lesson one</h1> 
    <p>Hello world!</p> 
  </body> 
</html>

In the HTML above, every node except for the document node has a parent node:

Most element nodes have child nodes:


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From http://www.w3schools.com (Copyright Refsnes Data)