AnAccess Control List (ACL)is a structured, system-maintained list of authorization rules that specifieswho or what is allowed to access a resourceand what actions are permitted. In many operating systems, network devices, and applications, an ACL functions as an internal table that maps identities such as user IDs, group IDs, service accounts, or even device/terminal identifiers to permissions like read, write, execute, modify, delete, or administer. When a subject attempts to access an object, the system consults the ACL to determine whether the requested operation should be allowed or denied, enforcing the organization’s security policy at runtime.

The description in the question matches the classic definition of an ACL as a computerized table of access rules tied to login IDs and sometimes the originating endpoint or terminal context. ACLs are central to implementingdiscretionary access controland are also widely used in networking (for example, permitting or denying traffic flows based on source/destination and ports) and file systems (controlling access to folders and files).

AnAccess Control Entry (ACE)is only a single line item within an ACL (one rule for one subject). A “Relational Access Database” is not a standard security control term for authorization tables. A “Directory Management System” manages identities and groups, but it is not the same as the enforcement list attached to a specific resource. Therefore, the correct answer isAccess Control List.