RDFS is a schema language for RDF. RDFS is a rather small vocabulary. Among others, it defines the following resources that are commonly used in ontology development:
RDFS also defines 4 annotation properties as well as a few other much less commonly used statements such as rdfs:Container.
All statements in the RDFS vocabulary are available in TopBraid Composer. They are shown in either Classes View or Properties View.
Unlike XML Schema, RDFS can not be used for validation. It is used to infer additional information based on the ontology schema and given (asserted) statements. RDFS ontology can never be semantically invalid.
Syntactical errors are possible (and even likely) when creating RDF in a text editor. Using ontology development tools such as TopBraid Composer ensures that there are no syntactic errors.
RDFS and OWL have formally defined semantics. It is defined in terms of inferences entailed by each RDFS or OWL statement. By entailed we mean, inferences that result from an asserted statement in RDF. RDFS definitions are as follows:
If a rdf:type rdfs:Class1 and rdfs:Class1 rdfs:subClassOf rdfs:Class2, then a rdf:type rdfs:Class2
If a property1 b and property1 rdfs:subpropertyOf property2, then a property2 b
If Class1 rdfs:domain property1 and a property1 b, then a rdf:type Class1
If Class2 rdfs:range property1 and a property1 b, then b rdf:type Class2