This document is a presentation of the Resource Description Framework (RDF) recommended by the World Wide Web Consortium (W3C), to model meta-data about the resources of the web. It is described in both documents  and ; the former focuses on syntactical aspects while the later addresses the definition of vocabularies (often named schemas). Though this is a pragmatic approach, I will use a slightly different plan, more suited to my own goals (using RDF in knowledge representation systems). The first section will describe the RDF model, which is its fundamental syntax. The second section will present the semantic aspects of RDF, the concepts and the corresponding vocabulary. The last section will describe the XML syntax proposed in .