Personas are a popular tool in "design thinking" and are useful for helping product owners, designers, and developers consider the needs of a "known" set of use

Personas are a popular tool in "design thinking" and are useful for helping product owners, designers, and developers consider the needs of a "known" set of user archetypes. The point is to see your app through their eyes, priorities, frustrations. Certainly there are users who don't fit any particular persona, but for the happy paths of your app, it's helpful to give a name to a few known "classes" of user.