Each XML document has one, and exactly one single root element. This element is also known as the document element. It encloses all the other elements and is therefore the sole parent element to all the other elements. content Within the document element, apart from any number of attributes and other elements, there may also be more optional text, comments, processing instructions and whitespace. A more expanded example of an XML document follows, demonstrating some of these extra nodes along with a single rootElement element. ]> text