Transformation is one of the most important and useful techniques for working with XML. To transform XML is to change its structure, its markup, and perhaps its content into another form. A transformed document may be subtly altered or profoundly changed. The process is carefully shaped with a configuration document variously called a stylesheet or transformation script.
There are many reasons to transform XML. Most often, it is to extend the reach of a document into new areas by converting it into a presentational format. Alternatively, you can use a transformation to alter the content, such as extracting a section, or adding a table of numbers together. It can even be used to filter an XML document to change it in very small ways, such as inserting an attribute into a particular kind of element.
Some uses of transformation are:
They may seem like magic, but transformations are a very powerful and not too complicated way to squeeze more use out of your XML.