Mainly, I was wondering what advantages the ontology languages of RDFS/OWL has over using a markup system (such as http://www.schema.org/) for managing and creating metadata?
I'm still very confused about how different concepts of the "Semantic Web" are supposed to fit together in the overall picture... The relation between RDF/RDFS/RDFa? OWL? URIs? and finally, XML and SQL/SPARQL? All the descriptions I've read about so far about them make sense individually, but I'm not sure if I could be able to use them as tools if someone were to tell me to implement and query an ontology, for instance. Or any simple examples that can be provided is greatly appreciated.