The term "Master Key" refers to a key that can open multiple locks, typically used in security systems. It allows authorized personnel to access various areas without needing a separate key for each lock. This is commonly used in hotels, offices, and large buildings to simplify access for maintenance and security staff. In a broader context, the concept of a master key can also apply to systems or methods that provide access to multiple resources or information. For example, in software, a master key might grant access to various features or data sets, enhancing efficiency and control for users like administrators or managers.