Good question,
The getElementAttribute returns an attribute used in a HTML tag.
For example <div class='myclass'></div> here class is an attribute.
The getElementProperty returns a property of a DOM node.
For example when you have a DOM node, it contains a property
clientLeft, this can be accesed with node.clientLeft
Note that many attributes are accessible as a property as well.
The getStyleAttribute is used to access styling information of a DOM
node.
so for example "background-color" is a style attribute which changes
the background color of the DOM node.
A DOM node normally has a property style that contains the different
style properties.
Hope this explains ?
David