Example 2     <<      >>       intro       contents     

There is exactly one element, called the root, or document element, no part of which appears in the content of any other element.

  Well-formed documents   HOME     

<book> is root element :

               <book>This is a book</book>
               
            

<list> is root element:

               <list>
               <item>Item 1</item>
               <item>Item 2</item>
               <item>Item 3</item>
               </list>
               
            

  Documents with errors   HOME     

Only one root element is permited:

               ???
               <item>Item 1</item>
               <item>Item 2</item>
               <item>Item 3</item> 
               ???