Adopted from the documentation:

The Element type is a flexible container object, designed to store hierarchical
data structures in memory. The type can be described as a cross between a list
and a dictionary.

Each element has a number of properties associated with it:

  * a tag. This is a string identifying what kind of data this element
    represents (the element type, in other words).
  * a number of attributes, stored in a Python dictionary.
  * a text string.
  * an optional tail string.
  * a number of child elements, stored in a Python sequence

The ElementTree class can be used to wrap an element structure, and convert it
from and to XML.

WWW: http://effbot.org/zone/element-index.htm