RDF (Resource Description Framework) is a standard model for data interchange on the Web.
RDF extends the linking structure of the Web to use URIs to name the subjects being discussed and to identify the type of relationships between subjects.
The basic data model of RDF is (subject, predicate, object). Using this simple model, it allows structured and semi-structured data to be mixed, exposed, and shared across different applications.
RDF also has features that facilitate data merging even if the underlying schemas differ, and it specifically supports the evolution of schemas over time.
The RDF structure forms a directed, labelled graph, where the edges represent the named link between two resources, represented by the graph nodes. This graph view is the easiest possible mental model for RDF and is often used in easy-to-understand visual explanations.