What is the purpose of an access control list (ACL)?

An access control list (ACL) serves the critical function of defining who is permitted to access specific resources within a computing environment. It essentially acts as a set of rules that outlines permissions for users or groups of users regarding what actions they can perform on particular resources, such as files, directories, network devices, or applications. By specifying permissions, an ACL helps enforce security policies and ensures that only authorized individuals can access sensitive information or utilize critical system functions. This mechanism is vital for protecting data integrity and confidentiality within any information system.

The other options do not align with the primary role of an ACL. For instance, increasing the speed of data transfer pertains more to network optimization techniques rather than access control. Similarly, storing backup copies is a matter of data management and disaster recovery, while eliminating viruses involves security measures like antivirus software, not access control.