For us, RDF is a universal syntax. Most syntaxes involve an encoding of information into a sequence of alphabetic symbols, but in RDF we use a directed labeled graph (instead of a sequence) and an alphabet of symbols big enough for everyone to use their own symbols. This design allows information from multiple sources to meaningfully co-exist.
Our low-level RDF operations, at roughly the level of looking at individual symbols in a sequence, involve adding Node-Arc-Node triples to a graph and searching a graph for triples matching a pattern.
Our high-level operations involve (1) transfering knowledge about objects between native forms (C++ classes) and their RDF encodings, and (2) translating between RDF graphs and traditional syntaxes.
RDF can also be seen as a weak Knowledge Representation language, and we support this perspectivae by allowing conversion of an RDF::Graph to and from an FOL::Sentence.