The memory system, whatever it may be for (human, animal, or inanimate), needs to be able to encode, store, and retrieve information effectively. Memory can fail if any of these functions stops working. ‘Mapping memories’ looks at how memory systems operation and how different functional memory components should be defined. How reliable are personal definitions of good and bad memory? In fact memory separates into multiple, distinct components. What is the difference between short-term and long-term memory? How can memory be subdivided? Everyday observations on memory are based on personal experience so objective evidence must come from science. What is the difference between explicit and implicit memory?