Which of the following best describes "access cards" in the context of access control?

Access cards are best described as physical devices used to grant or deny access. In the context of access control, these cards serve a critical function by enabling authorized individuals to enter restricted areas or access specific resources. They typically work in conjunction with card readers and electronic locking mechanisms, providing a secure means of managing and controlling entry points.

While access cards can sometimes be used for employee identification, their primary purpose extends beyond simply identifying individuals. They are instrumental in the overall security protocol, allowing for the precise control of who can access certain locations based on the permissions programmed into each card. In addition, the other options present limitations on the definition—temporary passes for visitors are different types of access credentials, not encompassing the full range of access control functionalities that access cards provide. Similarly, access cards are not utilized primarily for payroll data storage, nor are they exclusively for employee identification purposes. Thus, their role as physical devices is what makes them integral to access control systems.