TACACS+ (Terminal Access Controller Access-Control System Plus) is a protocol used for network device authentication, authorization, and accounting. It allows organizations to manage user access to network resources securely. TACACS+ operates over TCP, providing a reliable connection and encrypting the entire payload for enhanced security. This protocol is commonly used in conjunction with RADIUS (Remote Authentication Dial-In User Service) but offers more granular control over user permissions. TACACS+ separates the authentication, authorization, and accounting processes, making it easier to manage user roles and track their activities on the network.