When talking about a role, it refers to a certain role or type in which a person best manifests themselves, especially in creative professions such as actors or musicians. It is a kind of image or character that becomes the most natural for the performer and is most often used in their work. For example, if an actor often plays serious dramatic roles, then that is their role.
In everyday life, we can also talk about a role when discussing in which situations or roles a person feels most comfortable and natural. This can be useful to better understand oneself or others, as knowing one's role makes it easier to choose a profession or social role in which one can manifest themselves best.