Roles
Roles are the different user personas for the Drupal application and are granted to users that match that persona. An effective content management analogy ties to publications that have authors and editors. The two personas have two different functions: one to write content and one to review and approve content. In Drupal, a role is effective at establishing different personas.
This goes beyond just content-related use cases as Drupal can also leverage roles for performing specific administrative actions. Consider a human resources use case where new joiners need accounts on the Drupal application or accounts need to be revoked for those who leave. A specific role can be established that is just able to manage accounts.
Role entity
Like a user, a role is an entity. It is a very simple configuration entity that only has a name and is not fieldable. Given that the entity system allows for relationships between entities, a user entity has a one-to-many relationship with...
