Databases typically store data in a tabular format, where a table has set of columns and rows, like a spreadsheet.
However, IRL, we tend to think in statements of
Object. This is particularly true in the English language where word order is subject, verb, object (SVO). This information construct is known as
triples, or semantic triples. The W3C Resource Description Framework is a leading specification for organizing these statements into semantic triples.
As Lenhert describes here:
"One of the fundamental benefits of these RDF-based controlled vocabulary structures are their dual nature as being both human intelligible as well as machine readable (and, therefore, portable). Like their basic constituent subject-verb-object basis, ontologies convey rich meaning in relatively simple and compact statements, making them extremely useful in modeling complex knowledge environments."
The following diagrams express semantic triples in various terms.
Using the natural English SOV terms
Using common graph theory terms
Note that edges are both directional and labeled.