Arctic SDI Glossary of Terms defines interoperability as: The ability of different types of computers, networks, operating systems and applications to work together effectively, without prior communication, in order to exchange information in a useful and meaningful manner.
Or in other words, the possibility for users to integrate spatial data from different kinds of sources, without repetitive manual intervention, i.e. the datasets they retrieve from the infrastructure follow a common structure and shared semantics.
To achieve interoperability between systems and system components, international standards of the Open Geospatial Consortium (OGC, International Organisation for Standardization (ISO), World Wide Web Consortium (W3C) and domain-specific thesauri or ontologies, are essential.
To allow for the discovery of, and access to, relevant datasets that exist elsewhere, this guideline focus on the technical interoperability.
OGC defines interfaces that enable interoperability of geospatial applications. [OGC, Open Geospatial APIs – White Paper, http://docs.opengeospatial.org/wp/16-019r4/16-019r4.html]