Practical RDF: Sometimes you feel like RDF, sometimes you don't. (SOURCE:"burningb")-Excellent wine example clearly explains the difference between XML, RDF and ontologies and the uses of each!
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XML gives us the ability to record bits and pieces of data in a valid manner. RDF then builds on the data, piecing the bits and pieces together into complete statements. Ontologies then take these statements and builds machine-understandable inferential rules based around them. The result of all this working together is the wine scenario:
</quote> [Roland Tanglao: KLogs]