XML is Extensible, meaning, it is not restricted to a set of tags. You get to define the tags names as anything you would like. Also, there are a number of rules you must follow when writing XML tags which leads us to syntax. In between these is the data as you have seen in the above example. In certain cases, you will need to use attributes.
Attributes are just more information tucked into the XML tag.
Those are the rules you need to write your first XML document. Corp. All Rights Reserved.