Cerbos is an open-source authorization layer and access control system designed for implementing fine-grained permissions in applications. It provides a Policy Decision Point (PDP) that can be integrated into existing systems to handle authorization logic externally from the core application code. Cerbos supports both Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC) models, allowing for context-aware and granular access control policies. It offers a managed Policy Administration Point (PAP) through Cerbos Hub, enabling developers to implement flexible and dynamic access control policies, separating authorization logic from application code.