Personas describe different representative users, including their goals, pain points, and other relevant factors that could affect their design satisfaction and differentiate them from other users. They are never based on a single actual person, nor are they caricatures. They should feel like real people, with realistic sets of goals of behaviors.
While personas are not real people, it’s helpful to think of them as such in order to continue to have the users’ interests at the core of the project. Personas should include just enough detail to make them feel real, but not so much to distract from the things affecting their experience with the product.