The article discusses the roles of XML and RDF in the Semantic Web. XML is used for document structure, while RDF provides a data model that supports more sophisticated ontology representation techniques. The Semantic Web aims to enable machine-processable information, allowing intelligent services like information brokers and search agents. RDF is more suitable for applying ontology-representation languages like OIL to the task of interoperability. XML has limitations in semantic interoperability because it only describes grammars and does not provide a common interpretation of data. RDF, on the other hand, provides a basic object-attribute-value data model for metadata and allows for more flexible and expressive data modeling. RDF schema allows developers to define a particular vocabulary for RDF data and specify the kinds of objects to which these attributes can be applied. The article also discusses the challenges of using XML for semantic interoperability and argues that RDF is a more suitable foundation for the Semantic Web. The authors propose a method for encoding ontology representation languages into RDF/RDF schema and illustrate this with an example using OIL. The article concludes that RDF is a more suitable foundation for the Semantic Web and that further research is needed to develop more expressive ontology languages.The article discusses the roles of XML and RDF in the Semantic Web. XML is used for document structure, while RDF provides a data model that supports more sophisticated ontology representation techniques. The Semantic Web aims to enable machine-processable information, allowing intelligent services like information brokers and search agents. RDF is more suitable for applying ontology-representation languages like OIL to the task of interoperability. XML has limitations in semantic interoperability because it only describes grammars and does not provide a common interpretation of data. RDF, on the other hand, provides a basic object-attribute-value data model for metadata and allows for more flexible and expressive data modeling. RDF schema allows developers to define a particular vocabulary for RDF data and specify the kinds of objects to which these attributes can be applied. The article also discusses the challenges of using XML for semantic interoperability and argues that RDF is a more suitable foundation for the Semantic Web. The authors propose a method for encoding ontology representation languages into RDF/RDF schema and illustrate this with an example using OIL. The article concludes that RDF is a more suitable foundation for the Semantic Web and that further research is needed to develop more expressive ontology languages.