This book combines in an exemplary manner the theoretical aspects of a combination of intelligent conceptual and spatio-temporal queries of heterogeneous information systems. Throughout the book, examples are provided using GIS functionality. However, the theoretical concept and the prototypical system are more general. The ideas can be applied to other application domains and have been demonstrated and tested, e.g., in the electronics and tourist domains. This demonstrates well that the approaches worked out are useful for practical applications – a valuable benefit for those readers who are looking for actual research results in the important areas of data transformation, the semantic representation of spatial and/or temporal relations, and for applications of metadata.