The Semantic Web 

9.1 Introduction 

Semantic Web is an extension to the World Wide Web. The purpose of the semantic web is to  provide structure to the web and data in general. It emphasizes on representing a web of data  instead of web of documents. It allows computers to intelligently search, combine and process  the web content based on the meaning that the content has. Three main models of the semantic  web are: 

1. Building models 

2. Computing with Knowledge 

3. Exchanging Information 

∙ Building Models: 

Model is a simplified version or description of certain aspects of the real-time entities.  Model gathers information which is useful for the understanding of the particular domain. ∙ Computing Knowledge: 

Conclusions can be obtained from the knowledge present. 

Example: If two sentences are given as ‘John is the son of Harry’ and another sentence  given is- ‘Hary’s father is Joey’, then the knowledge that can be computed from it is  – ‘John is the grandson of Joey’ 

Similarly, another example useful in the understanding of computing knowledge is- ‘All A is B’ and ‘All B is C’, then the conclusion that can be drawn from it is – ‘All A are C’ respectively. 

∙ Exchanging Information: 

It is an important aspect. Various communication protocols have been implemented for the  exchange of information like the TCP/IP, HTML, WWW. Web Services have also been  used for the exchange of the data. 

The technologies associated with the semantic web are: 

∙ RDF (Resource Description Framework) 

∙ OWL (Web Ontology Language) 

∙ DL (Description Language) 

The query language used is: 

∙ SPARQL ( SPARQL Protocol and RDF query language). 

∙ SHACL (Shape Constraint Language). SHACL is used for validating the RDF graphs  against a set of conditions.