We have been hearing the Semantic Web is going to be the next phase of the World Wide Web, the W3.0. What is Semantic Web? The standard answer is that it is the status of ‘Web of data’
W3C (The World Wide Web Consortium) is an organisation leading the full potential of World Wide Web by developing protocols and guidelines that ensure the long-term growth the web. In its webpage of Semantic Web, it says:
“The term “Semantic Web” refers to W3C vision of the Web of linked data. Semantic Web technologies enable people to:
– create data stores on the Web,
– build vocabularies,
– and write rules for handling data.”
It will be easier to understand if we look at a traditional library collection. We build our collection – that is the data stores. We use standard vocabularies to describe the items in our collections. We follow the established metadata standards (AACR, RDA, MARC21, Dublin Core). These are the agreed rules of handling data.
In order to build a web of data, there are four areas to look at:
“1. Linked Data: The Semantic Web is a Web of data — of dates and titles and part numbers and chemical properties and any other data one might conceive of. RDF provides the foundation for publishing and linking your data. Various technologies allow you to embed data in documents (RDFa, GRDDL) or expose what you have in SQL databases, or make it available as RDF files.
2. Vocabularies: At times it may be important or valuable to organize data. Using OWL (to build vocabularies, or “ontologies”) and SKOS (for designing knowledge organization systems) it is possible to enrich data with additional meaning, which allows more people (and more machines) to do more with the data.
3. Query: Query languages go hand-in-hand with databases. If the Semantic Web is viewed as a global database, then it is easy to understand why one would need a query language for that data. SPARQL is the query language for the Semantic Web.
4. Inference: Near the top of the Semantic Web stack one finds inference — reasoning over data through rules. W3C work on rules, primarily through RIF and OWL, is focused on translating between rule languages and exchanging rules among different systems.”