Since the early 1990s, interoperability of spatial data has been a major concern in the spatial information community (standardization bodies, research community, developers and users). However, the recent increase in the number of data sources and their widespread availability on Internet have emphasized the interoperability difficulties. One major concern is to deal with the interoperability of spatial data in their global context, that is to take into consideration their intrinsic semantics in combination with the semantics of their spatial and temporal properties. Doing so requires a more global approach that we have named geosemantics. In this paper, we present the concepts of geosemantics and geosemantics proximity. Hence, we begin with a conceptual framework for spatial data interoperability based on human communication, cognition, and ontology. The spatial characteristics involved in this framework are emphasized. Then geosemantic proximity is explained, especially the comparison of contextual properties which provide concepts and conceptual representations with real world semantics. Finally, we describe how it can be used to evaluate qualitatively the semantic similarity between spatial concepts and spatial conceptual representations in order to facilitate the work of the user who looks for the spatial data that best fit his needs.