public abstract String getTagName ()

The name of the element. If Node.localName is different from null, this attribute is a qualified name. For example, in:

 <elementExample id="demo"> ...
 </elementExample> , 
tagName has the value "elementExample". Note that this is case-preserving in XML, as are all of the operations of the DOM. The HTML DOM returns the tagName of an HTML element in the canonical uppercase form, regardless of the case in the source HTML document.