Link: RissRoss: The Dream Team.
First, why does it seem the same URI is used for all XSL stylesheets when the Dummies book says URIs are unique? Second, I am confused as to what a root node is. In the Dummies book, it says that a root node "contains all elements, including the document element." However, I thought the document element encompassed all the information. Therefore, what exactly is the root node? the book says it is invisible, and therefore the concept of a root node is hard to comprehend.
The URI is the same because you are using it to indicate that you are doing an XSL stylesheet. Think of that statement as saying simply, "I am making an XSL stylesheet". You always say that with the same URI with each stylesheet, but the URI to indicate you are creating a stylesheet vs. something else is unique.
The root node (not element) is confusing. It is a concept specific to XSLT and means simply what they say in the book, i.e., the very top of the document before anything else. The document element (also called the document root or root element just to make it worse) is the element that encloses all other elements in an XML document. Generally, these differences do not make much difference. However, when you write an XSLT template to match the root node, you need to understand that the root element will be one of its descendants.