Question:What are XML name spaces? 

In XML namespaces are a collection of names that is identified by a Uniform Resource Identifier (URI) which is always unique

Question:What is Xpointer? 

Xpointer is a separate language that contains a series of location terms that specifies a location in the document tree.

Question:What are the goals of XML data schema language? 

(a) Special tools should not be required for maintaining schema documents.
(b) XML and HTML authors should not have to learn a new syntax to express schema information.
(c) Schema should be extensible.
(d) Xml data must be upwardly compatible with XML 1.0.

Question:What XML data island? 

XML data island allow authors to insert XML fragments directly into an HTML document.