Capability Table and ACLs

An access control matrix is a mechanism used to associate access permissions of a
subject to an object. The actual permissions assigned to a subject,which is a row
within the access control matrix, is referred to as a capability table. And the different
subjects that can access an object are referred to as an access control list
(ACL), which are the columns of the matrix, as shown in Figure 2-7.
When a subject requests to access a specific object, the operating systemwill refer
to this access control matrix to see if the access and requested operation is allowed.