SELinux is a Linux feature that:

While SELinux does monitor access, its primary function is to enforce policies and prevent unauthorized access, not merely to warn users about attempts.

SELinux is designed as a flexible MAC framework that supports various access control models, including Role-Based Access Control (RBAC) and Type Enforcement (TE), not solely a single form of MAC.

SELinux (Security-Enhanced Linux) is a kernel security module that enforces Mandatory Access Control (MAC) policies, which rigorously define and restrict what user-space programs and system services can access and do, even if they are compromised. This provides a robust layer of security beyond traditional Discretionary Access Control.

SELinux enforces policies on access to files and other resources; its direct function is to prevent unauthorized actions based on its policy rules, rather than solely ensuring files are not modified and alerting, which is more typical of file integrity monitoring.