Personas are fictional but research-based representations of key user types. First developed and popularised by Alan Cooper in the 1990s, they give design teams a concrete, human face to design for rather than an abstract average user. A well-crafted persona distils research findings into a memorable character whose goals, frustrations, behaviours, and contexts the team can refer to throughout a project. The goal is not demographic accuracy but motivational and behavioural truth grounded in real data.