What is the difference between RDF Schema and Ontology?

Question

I am new to Semantic Web and confused regarding RDFs and Ontology. Can someone explain the difference between RDF Schema and Ontology?

Answer 1

RDF Schema (RDFS) is a language for writing ontologies.

An ontology is a model of (a relevant part of) the world, listing the types of object, the relationships that connect them, and constraints on the ways that objects and relationships can be combined.

A simple example of an ontology (though not written in RDFS syntax):

class: Person
class: Project
property: worksOn

worksOn domain Person
worksOn range Project

which says that in our model of the world, we only care about People and Projects. People can work on Projects, but not the other way around.