Merging Operation for Domain Ontologies in Semantic Web: Some Issues

In the Semantic Web era, ontologies are an essential component for the Semantic Web to represent, process, share knowledge in different domains. It is mainly defined as a vocabulary for Semantic Web to describe a particular domain with meanings of used terms. As ontologies are increasing day by day, so there is requirement or ontology management that involves ontology mapping, merging, creation, reuse, etc. Ontology provides interoperability among different Semantic Web applications across the heterogeneous system. For this ontology, merging and mapping tasks are used to join multiple ontologies to produce accurate, consistent merged ontology for interoperability among heterogeneous systems. This paper presents different techniques used for ontology merging, their characteristics, and the tools used for ontology merging.