Resource Description Framework

Created on Feb. 6, 2013, 1:42 p.m. by Hevok & updated by Hevok on May 2, 2013, 5:16 p.m.

The Resource Description Framework (RDF) provides means to structure knowledge in the form of small Triple facts.

The Resource Description Framework is a Language for encoding Knowledge on Web Pages to make it understandable to electronic Agents searching for Information [Brickley and Guha, 1999].

RDS belongs to the Information Exchange Layer of the Semantic Web Technology Stack.

In the Information Exchange Layer we can represent knowledge in the same way we can state Facts and communicate about these Facts. Representing a Fact is pretty simple, it is somehow in RDF like in pretty simple sentences in our Natural Language, because every bit of knowledge, every fact consists out of a Subject (what it refers to), a Property (which means the Subject has a specific Property) and an Objects (which means the Property has a specific Value).

So, Subject, Property and Object form a simple fact in RDF. This is the way how knowledge is represented in the Semantic Web and machines can read it (i.e. it is Machine-Understandable).

In RDF everything can in principle a resource and resources are identified via unique URI. Resources need to be described. This is done with the help of properties and Relationships among these resources. This Relationships can be represented as Graphs. RDF provides a Framework which is a combination on Web-based protocols and it is based on formal model which means that it has a formal Semantics that is well defined and is sound. This allows to identify Relationships among Resources as well as to handle this knowledge with a formal Semantics that we can deduce new knowledge from implicit hidden knowledge inside this Resource Description Framework.

Knowledge in RDF is simple nothing else than a list of statements and allow this statements follow a pretty simple schema of Subject, Property and Object.

Hevok (Subject)
is located at (Property)
Denigma (Object)
  • knowledge in RDF is expressed as a list of statements
  • all RDF statements follow the same simple schema.

Subject and Object can be resources and these resources can be addressed via URIs. The Property is nothing else than the attribute for description of resources is also an URI, i.e. it can be denoted with an URI. The property has a value and value might be another resource or might also be, if it is descriptive data, a string or simply characters (i.e. Literal).

Thus, RDF Triples are composed of three parts: subject (which is a URI),a Property (which is also an URI) and a Object which might be an URI, if it is referring to another Resource or it might be a Literal, if it referrers to a String or a Value that has an associated Datatype.

RDF can be extended with more expressive Constructs aimed at facilitating Agent Interaction on the Web [Hendler and McGuiness, 2000]


Brickley, D. and Guha, R.V. (1999). Resource Description Framework (RDF) Schema Specification. Proposed Recommendation, World Wide Web Consortium:

Hendler, J. and McGuinness, D.L. (2000). The DARPA Agent Markup Language. IEEE Intelligent Systems 16(6): 67-73.


Tags: knowledge, structure, facts, framework
Categories: Tutorial, News
Parent: Semantic Web
Children: Blank Node, Domain, Limits of RDF(S), List, Literal, Range, RDF, RDF Model, RDF Representation, RDF Schema, RDF-Graph, Reification, Simple Facts in RDF, SPARQL, Storing RDF Data, Turtle

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