Today, instead of keys, we carry access cards or ID badges to gain entry to secured areas. Access control systems can also be used to restrict access to workstations, file rooms housing sensitive data, printers, as well as entry doors. In larger buildings, exterior door access is usually managed by a landlord, or management agency, while interior office door access is controlled by the tenant company.
People new to access control may think the system is made up only of the card and the card reader mounted on the wall next to the door. There are a few more parts behind the scenes, all working together to make the magic of granting access to the right person.