Interoperability is the degree to which a software system can exchange and use information from another software system. In order for two systems to interoperate in a useful manner, they must be capable of communicating with each other (syntactic interoperability) as well as be able to interpret the information exchanged in a meaningful and correct way (semantic interoperability).
The term interoperability is related to, and sometimes used interchangeably with, the term integration.