Hierarchical Tree [1/18]
Any HTML document is an hierarchical tree. It means that each element has at most one parent, i.e., the element nesting it. Only the root element has no parent. Let's take a simple page:
<html> <head></head> <body> <p>Document text</p> <p class="text">Highlighted <span>line</span></p> </body> </html>
You can draw the following hierarchical tree for this page:
It outlines the structure of nesting of elements. This example shows that
span element's parent is
body as a parent.
The document's hierarchical structure defines the basics of property inheritance in it .