Network Access Control (NAC) is a security solution that helps organizations protect their networks from unauthorized access by enforcing policies and ensuring that devices meet certain security requirements before granting access. NAC solutions can be used to control access to wired and wireless networks, virtual private networks (VPNs), and remote access systems. At its core, NAC is designed to prevent unauthorized access to a network by identifying and authenticating users and devices, and enforcing security policies to ensure that only authorized users and devices are granted access. NAC solutions can also monitor and manage network traffic to identify potential security threats and prevent data breaches.