Handbook of metadata semantics and ontologies Metadata research has emerged as a discipline cross cutting many domains focused on the provision of distributed descriptions (often called annotations) to Web resources or applications. Such associated descriptions are supposed to serve as a foundation for advanced services in many application areas including search and location personalization federation of repositories and automated delivery of information. Indeed the Semantic Web is in itself a concrete technological framework for ontology based metadata. For example Web based social networking requires metadata describing people and their interrelations and large databases with biological information use complex and detailed metadata schemas for more precise and informed search strategies. There is a wide diversity in the languages and idioms used for providing meta descriptions from simple structured text in metadata schemas to formal annotations using ontologies and the technologies for storing sharing and exploiting meta descriptions are also diverse and evolve rapidly. In addition there is a proliferation of schemas and standards related to metadata resulting in a complex and moving technological landscape hence the need for specialized knowledge and skills in this area. The Handbook of Metadata Semantics and Ontologies is intended as an authoritative reference for students practitioners and researchers serving as a roadmap for the variety of metadata schemas and ontologies available in a number of key domain areas including culture biology education healthcare engineering and library science.