  This paper investigates and briefly describes the major currently existing
problems with World Wide Web .i.e., Information filtration and Security became
the main reasons of semantic web's invention. The semantic web claims of
providing the semantic based solutions towards current web problems. Semantic
web have introduced and relies on a main building block "Ontology" to provide
the information in machine processable semantic models and produce semantically
modelled knowledge representation systems. This paper also describes the role,
construction process and the contributions of ontology in providing some in
time proposed and implemented solutions. Furthermore paper concludes with the
currently existing limitations in Ontology and the areas which need
improvements.
