An access control vestibule, often referred to as a 'mantrap', is a physical security measure consisting of two sets of interlocking doors. The primary purpose of this arrangement is to trap an individual in a space between two sets of doors until authentication is verified, thereby preventing tailgating and ensuring only authorized access. A turnstile, although used for individual entry control, does not provide a space for trapping and verifying individuals between two sets of doors. A biometric scanner is a type of authentication device but does not refer to the interlocking door mechanism itself. A locked server rack provides physical security for the hardware but does not control individual access to larger secure areas in the manner of a vestibule.