What is an access control list (ACL)?

An access control list (ACL) is fundamentally a list of permissions attached to an object, such as files, directories, or network resources. ACLs define what actions are permitted or denied for specific users or groups of users regarding that object. For instance, an ACL may specify whether a user can read, write, or execute a file. This fine-grained control is essential for enforcing security policies within a system and ensuring that users have access only to the resources they require for their roles.

This concept is crucial in various contexts, such as file systems, network devices, and cloud resources, where managing access is vital for security and compliance. The clarity and specificity of ACLs help organizations to implement least privilege access, minimizing the risk of unauthorized access or modifications to sensitive data.

The other options do not accurately define an ACL. A list of user credentials for access pertains to authentication rather than authorization, which is the domain ACLs operate within. A document outlining general security policies would generally cover broader security guidelines and practices rather than specific access permissions. A database of network security configurations might include many elements, but it does not specifically denote the granularity of access rights that an ACL provides.