Episodic memory
Endel Tulving originally described episodic memory as a record of a person's experience that held temporally dated information and spatio-temporal relations. A feature of episodic memory that Tulving later elaborates on is that it allows an agent to imagine traveling back in time. A current situation may cue retrieval of a previous episode, so that context that colours the previous episode is experienced at the immediate moment. The agent is provided with a means of associating previous feelings with current situations. Semantic memory, on the other hand, is a structured record of facts, concepts, and skills that we have acquired. Semantic information is derived from accumulated episodic memory. Episodic memory can be thought of as a "map" that ties together items in semantic memory. For example, all encounters with how a "dog" looks and sounds will make up the semantic representation of that word. All episodic memories concerning a dog will then reference this single semantic representation of "dog" and, likewise, all new experiences with the dog will modify the single semantic representation of that dog.