Learn in the textbookBasic Frameworks of Marketing Strategy
DefinitionPositioning (ポジショニング) is the step of setting, for the target customers, the key points of differentiation (差別化) between one's own product and competing ones, and deciding where it stands in customers' minds.
ExplanationIt comes after segmentation and targeting have fixed the target group, and it sorts out differences from competitors along axes customers care about, such as affordability or the range of features. Once the axes that show the difference are set, it becomes easier to decide how to combine the 4P to match.
AnalogyPicture several lunch-box shops on the same street: one promotes big portions at low prices, another promotes healthy, vegetable-centered meals, so each gives customers a different reason to remember it.
Memory hookPosition means place: imagine a map in the customer's head and push your own pin into a spot away from the competitors' pins.