Power BI development ensures security by applying features such as row-level security (RLS), which restricts data access based on user roles. Power BI development also use role-based access control (RBAC) to assign specific permissions to different users or groups, ensuring that sensitive information is only accessible to authorized personnel. Data encryption is applied both in transit and at rest to safeguard information. Additionally, Power BI integrates with Azure Active Directory for secure authentication, allowing administrators to manage user identities and access rights effectively across the organization.