It is often implicitly assumed by researchers that their readers understand what cognitive map and cognitive mapping are, and their justification for study. This paper differs in this respect by explaining explicitly the ‘what’ and ‘why’ questions often asked, demonstrating cognitive mapping's multidisciplinary research worth. First, it examines questions concerning what cognitive maps are, the confusion inherent from the use of the term ‘map’, and the usage and reasons for alternative expressions. Second, it examines the theoretical applications or conceptual research, concerning cognitive maps role in the influencing and explaining spatial behaviour; spatial choice and decision making; wayfinding and orientation; and the cognitive maps utility and role as a mnemonic and metaphorical devise; a shaper of world and local attitudes and perspectives; and for creating and coping with imaginary worlds. Third, it discusses cognitive mapping's practical and applied worth, concerning the planning of suitable living environments; advertising; crime solving; search and rescue, geographical educational issues, cartography and remote sensing; and in the designing and understanding computer interfaces and databases, especially Geographical Information Systems (GISs).