Correspondences between entities inhering in regions of the conceptual system. Some mappings are relatively stable and persist in long-term memory while others are temporary associations set up due to dynamic processes of meaning-construction. Mappings which hold in long-term memory are most commonly associated with conceptual metaphor theory and are known as cross-domain mappings. Mappings which are more temporary in nature and serve to associate two regions of conceptual space for the purposes of situated understanding are most commonly associated with processes of conceptual projection dealt with in mental spaces theory.