Comprehensive and Detailed 100 to 150 words of Explanation From ServiceNow Human Resources topics:

Roles are the foundational security mechanism in ServiceNow used to control access to applications, modules, and specific features. In the context of HRSD, roles like sn_hr_core.admin or sn_hr_core.case_reader determine which parts of the HR application an employee can interact with. While 'User Authentication' verifies who the user is, it is the Roles assigned to that user (often via Group membership) that grant the actual permissions to view the HR Case Management module or the HR Profile application. This role-based access control (RBAC) ensures that sensitive data is compartmentalized, preventing unauthorized users from accessing confidential modules. For instance, a general employee might only have a client role to access the Portal, while an HR professional requires specific scoped roles to manage the backend HR modules.

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