I am new to Semantic Web and confused regarding RDFs and Ontology. Can someone explain the difference between RDF Schema and Ontology?
Conceptually there is no difference, i.e., RDFS can be utilised to create a (e.g. domain specific) vocabulary or ontology, where RDFS is bootstrapping itself in companion with RDF (everything is at least an rdfs:Resource). Furthermore, in the context of Semantic Web technologies you could utilise OWL to describe advanced semantics of your ontology/vocabulary. See also this definition of ontology.