An access control system is a security framework designed to regulate and restrict which authenticated entities—users, devices, or applications—can interact with specific resources within an organization. As a core component of Identity & Access Management (IAM), it combines authentication protocols that verify an entity's identity with authorization mechanisms that determine what actions and data that entity is permitted to access, modify, or delete.

These systems protect both digital assets (networks, databases, applications) and physical facilities by enforcing the principle of least privilege, ensuring users receive only the minimum permissions necessary for their roles. By continuously managing and monitoring access throughout a user's lifecycle, access control systems mitigate risks from unauthorized access, data breaches, and insider threats while supporting regulatory compliance and organizational security resilience.