What role do user roles play in Mendix applications?

User roles are fundamental in Mendix applications as they define access rights and permissions for different types of users. This functionality is crucial because it allows you to control what actions users can perform and what data they can view, depending on their assigned role. For instance, a user with an admin role may have extensive access to all functionalities within the application, while a regular user might be restricted to viewing only specific data or performing certain actions. This system ensures security, maintains data integrity, and enhances the overall user experience by tailoring the application to meet varied user needs based on their roles.

In contrast, the other options do not accurately capture the essence of user roles. Limiting the number of application users isn't a function of user roles—this is typically managed through licensing and deployment settings. While user roles may influence reporting, they are not solely used for that purpose. Additionally, enforcing coding guidelines is unrelated to user roles, as that pertains more to the development process and best practices within the Mendix platform rather than user access and permissions.