FGA and ABAC are two distinct authorization models used to manage access in modern access control systems. FGA is a comprehensive framework that integrates multiple authorization models, including Attribute-Based Access Control (ABAC), Relationship-Based Access Control (ReBAC), and Role-Based Access Control (RBAC). It enables organizations to define permissions based on various factors such as user attributes, resource properties, environmental context, and relationships between entities. In contrast, ABAC is a specialized model within FGA that governs access exclusively through attributes associated with users, resources, actions, and environmental conditions. While ABAC can be difficult to manage due to the need to track and update relevant attributes, FGA systems make it easier by using modular policies, allowing teams to combine different models when needed. The choice between FGA and ABAC depends on the organization's specific needs, with FGA often coming out on top due to its ability to integrate multiple models and adapt to complex scenarios. Additionally, both models have their strengths in terms of security, performance, and scalability, but also present challenges such as managing complexity and maintaining up-to-date data. As digital ecosystems grow more interconnected, the fusion of these models powered by advances in centralized policy engines and real-time data pipelines will define the next generation of access control systems.