In the context of access control measures, what is a vestibule typically used for?

A vestibule is typically used as an entry area that allows for controlled access. This physical space functions as a transition zone between the public and private areas of a facility or building. By having a vestibule, organizations can implement access control measures that limit entry to authorized personnel only. It serves to enhance security, allowing for identification checks, enabling a space where individuals can be vetted before they gain access to more secure areas.

In comparison, the other options presented do not accurately reflect the primary function of a vestibule. Storing sensitive data securely pertains to data storage solutions rather than physical access management. Monitoring network traffic is related to cybersecurity practices that involve the analysis of data flows rather than controlling physical access to a location. Lastly, a secure online database concerns virtual security and information storage, which is not applicable to the physical context of access control that a vestibule provides.