Hello Tina, Thank you very much for your interest for the Semantic Web. This mailling list is specifically dedicated to a tool, Apache Jena. It's like asking about astronomy on a list dedicated to a brand of telescopes : it's off-topic.
The Wikipedia article about the Semantic Web is a very good start : https://en.wikipedia.org/wiki/Semantic_Web If you're fond off asking humans, I suggest you ask your question to the following list, you will certainly get more answers : http://lists.w3.org/Archives/Public/semantic-web/ Have a nice trip on the paths of the Web of data :) Colin -------- Original Message -------- Subject: Re: Web 3 vs Web 2 Local Time: June 7, 2017 1:25 PM UTC Time: June 7, 2017 11:25 AM From: admo...@gmail.com To: users@jena.apache.org To see the metadata you have to consider the prefix statements that must be made before you can use the triples in your example/ @prefix rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# click on the hyperlink to follow it. Using this prefix statement adds metadata essential to understanding the triple: Student rdf:type Person rdf:type means: rdf:type a rdf:Property ; rdfs:isDefinedBy <http://www.w3.org/1999/02/22-rdf-syntax-ns#> ; rdfs:label "type" ; rdfs:comment "The subject is an instance of a class." ; rdfs:range rdfs:Class ; rdfs:domain rdfs:Resource . The object “Person” in the triple may also have metadata associated with it. If the prefix: @prefix foaf: http://xmlns.com/foaf/0.1/ is used the metadata associated with foaf:Person is <rdfs:Class rdf:about="http://xmlns.com/foaf/0.1/Person"; rdfs:label="Person" rdfs:comment="A person." vs:term_status="stable"><rdf:type rdf:resource="http://www.w3.org/2002/07/owl#Class"/><owl:equivalentClass rdf:resource="http://schema.org/Person"/><owl:equivalentClass rdf:resource="http://www.w3.org/2000/10/swap/pim/contact#Person"/><!-- <rdfs:subClassOf><owl:Class rdf:about="http://xmlns.com/wordnet/1.6/Person"/></rdfs:subClassOf> --><rdfs:subClassOf><owl:Class rdf:about="http://xmlns.com/foaf/0.1/Agent"/></rdfs:subClassOf><!-- <rdfs:subClassOf><owl:Class rdf:about="http://xmlns.com/wordnet/1.6/Agent"/></rdfs:subClassOf> --><rdfs:subClassOf><owl:Class rdf:about="http://www.w3.org/2003/01/geo/wgs84_pos#SpatialThing"; rdfs:label="Spatial Thing"/></rdfs:subClassOf><!-- aside: are spatial things always spatially located? Person includes imaginary people... discuss... --><rdfs:isDefinedBy rdf:resource="http://xmlns.com/foaf/0.1/"/><!-- <owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Document"/> this was a mistake; tattoo'd people, for example. --><owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Organization"/><owl:disjointWith rdf:resource="http://xmlns.com/foaf/0.1/Project"/></rdfs:Class> So you can see even a simple statement like Student rdf:type foaf:Person contains a huge amount of metadata that can be located and used by a machine! On 7/6/17, 1:07 am, "tina sani" <tinamadri...@gmail.com> wrote: For example, there is an rdf document about a student. Student rdf:type Person. Student hasName name. Student hasAdress adress Student study Course. Where is the meta data here. How machines understand this data.
