An access control vestibule is a physical security mechanism that consists of a small room or chamber with two doors, one leading to the outside and one leading to the secure site. The doors are controlled by an electronic system that verifies the identity and authorization of the person entering before allowing access to the next door. A landing page is a web page that appears when a user clicks on a link or advertisement. A smart locker is a physical security mechanism that allows users to store and retrieve items using a code or biometric authentication. A firewall is a network security device that monitors and filters incoming and outgoing traffic based on predefined rules. References: [CompTIA Network+ Certification Exam Objectives], Domain 4.0 Network Operations, Objective 4.1: Explain the importance of documentation and diagrams, Subobjective: Physical security devices (locks, cameras, etc.)