Chapter 13. Using XML Namespaces
As you saw in the previous chapter, a namespace is a collection of related elements and attributes, identified by a namespace name. This namespace name must be unique, and is often referred to by its abbreviated name or prefix.
Namespaces are most often used to distinguish identically named elements from one another. Specifically, namespaces help to distinguish global elements that are identically named, since local elements and attributes are generally made unique by their context.
This combination of namespace name plus an element name is called an expanded name. Because a namespace name must be unique, the expanded name will also be unique. (Note: This combination is also referred to as a universal name, qualified ...