Hi, The XML file is comprised of nodes, in your case a table node, a row node, CustomerID node, etc, etc.
These are quite simply the names of the nodes.
The data is the bit that comes between the opening and closing tags. For example, your first CustomerID tag has:
An opening tag: <CustomerID>
a closing tag: </CustomerID>
To extract this data you could use something called XPath.
A great place to start learning about these technologies is W3Schools.