How to create ontolology statement?

I want to know how to define an OWL statement开发者_如何学Python. The RDF uses three triplet; what is the difference between RDF and OWL?

OWL statements are just RDF statements that use predicates from the defined OWL vocabulary to (meta-)describe a vocabulary.

In RDF/XML, which seems to be your target, here is an example of the definition of an Object Property.

<!-- http://jug.basistech.com/2011/01/rex-entity#withinOrganization -->

<owl:ObjectProperty rdf:about="&rex;withinOrganization">
    <rdfs:label>withinOrganization</rdfs:label>
    <rdfs:comment>Determines in which organization is the position</rdfs:comment>
    <rdfs:domain rdf:resource="&rex;JobPosition"/>
    <rdfs:range rdf:resource="&rex;Organization"/>
    <rdfs:subPropertyOf rdf:resource="&rex;ruleRelationship"/>
</owl:ObjectProperty>

Here is a portion of the above as raw triples, which are in some ways clearer.

<http://jug.basistech.com/2011/01/rex-entity#withinOrganization> 
 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> 
 <http://www.w3.org/2002/07/owl#ObjectProperty> 
  .
<http://jug.basistech.com/2011/01/rex-entity#withinOrganization> 
<http://www.w3.org/2000/01/rdf-schema#label> "withinOrganization"   
.
<http://jug.basistech.com/2011/01/rex-entity#withinOrganization> 
 <http://www.w3.org/2000/01/rdf-schema#comment> 
   "Determines in which organization is the position"  .

In practical terms, download Protege or TopBraid if you want to make up an Ontology, or (e.g.) Jena if you want to do this in Java code.