As you have seen throughout this book, XML is a great technology to deal with data warehousing, data representation, data presentation, and more. A problem area in XML, however, is how to represent metadata in a standard way.
Metadata is quite literally data about data. You might find a dataset that makes little sense without the context surrounding it. Perhaps it would make better sense if it had some relations in place that map to additional data points or if it were related to existing data points to show a larger set of relations across boundaries.
An easy-to-understand structure surrounding metadata not only helps you comprehend the data you are presented with, but also gives you a mechanism to discover this data.
For instance, if you are conducting a search for the word Hemingway, you find all sorts of information that utilize this keyword. But do you want to know about books on the life of Ernest Hemingway, movies starring Mariel Hemingway, or information on the books written by author Ernest Hemingway?
This is where the relationships between the data make sense. Having data relations in place enables you to more easily pinpoint the data and facilitates research and data discovery that would be difficult otherwise. This chapter takes a look at how to use the Resource Description Framework (RDF) to create the metadata around any data that you represent in your XML documents.
RDF does a good job of structuring ...