There are two key characteristics of RDF stores (aka triple stores): the first and by far the most relevant is that they represent, store and query data as a graph. The second is that they are semantic, which is a rather pompous way of saying that they can store not only data but also explicit descriptions of the meaning of that data. The RDF and linked data community often refer to these explicit descriptions as ontologies. In case you’re not familiar with the concept, an ontology is a machine-readable description of a domain that typically includes a vocabulary of terms and some specification of how these terms inter-relate, imposing a structure on the data for such domain. This is also known as a schema. In this post, both terms schema and ontology will be used interchangeably to refer to these explicitly described semantics. Continue reading “Building a semantic graph in Neo4j” →