What does ACL stand for in the context of operating system security?

In the context of operating system security, ACL stands for Access Control List. An Access Control List is a foundational security mechanism used to define and manage permissions attached to various objects, such as files, directories, and network resources. Each entry in an ACL specifies which users or groups have access to the object and what operations they are authorized to perform, such as read, write, or execute.

ACLs are essential for ensuring that only authorized users can access sensitive data or system resources, thereby helping to maintain confidentiality, integrity, and availability within an operating system. By employing ACLs, administrators can implement fine-grained access control policies tailored to the specific needs of an organization, thereby enhancing overall security and compliance with regulatory requirements.

The other options provided do not accurately represent the concept of ACLs within operating system security. Access Controlled Ledger and Attempted Control List do not correspond to recognized security terminologies, while Access Communications List does not apply to the context of permissions and access management in operating systems.