access control entry (ACL) (ACE)
An Access Control Entry(ACE) is an entry in an access control list and describes the access rights that belong to a particular security ID( SID).
The Access Control Entry is evaluated by the operating system to determine effective access for a particular program based on authorization. When a user logs into a computer and runs a program, it uses the authorization and the user-specific account.
There are different Access Control Entries used by the security system to specify the different user rights.