What is a "master key" in the context of access control?

A master key in the context of access control is designed to open multiple locks within a particular system. This type of key is especially beneficial in settings where different locks are needed for various areas but oversight or access requires a single key for convenience and management efficiency.

In systems involving multiple locks, having a master key simplifies access for authorized personnel, such as managers or security staff. This allows them to have unrestricted access to all sections of the premises without needing a separate key for each lock. For example, in a hotel, a master key would enable staff to open guest room doors, service areas, and other secured locations without carrying a large collection of keys.

The other options describe different security concepts. A key that only opens one specific lock cannot be considered a master key, as that would limit its functionality. A digital code used for access refers to a different method of security, typically involving keypad entry or similar systems. Lastly, a lock that requires a fingerprint to open represents biometric security, which is unrelated to the concept of a master key.