What is an access control list (ACL)?

An access control list (ACL) is a security mechanism used to specify which users or groups have access to certain resources and what level of access is permitted. In this case, the correct answer highlights that an ACL consists of a list of permissions associated with an object, such as files, directories, network devices, or services. Each entry in the ACL defines what operations (like read, write, or execute) a particular user or group is allowed to perform on the associated object.

The concept of ACLs is crucial in user account management because they directly influence how resources are secured and accessed in a computing environment. By maintaining precise control over permissions, organizations can enforce security policies, ensuring that only authorized personnel can perform specific actions, thus protecting sensitive information.

The other choices do not correctly define ACLs. A list of user roles refers to categorizing users based on their roles within the organization rather than the permissions attached to specific objects. A record of user login attempts pertains to tracking user activity rather than managing access to resources. A document outlining organizational policies is typically focused on governance and procedures, without specific reference to permissions on resources.