Access Control Entry (ACE)
Definition - What does Access Control Entry (ACE) mean?
Access control entries (ACE) are entries in an access control list containing information describing the access rights related to a particular security identifier or user. Each access control entry contains an ID, which identifies the subject group or individual. An access control list may have several access control entries with each one defining the access rights of different groups or individuals.
Techopedia explains Access Control Entry (ACE)
The access control entries present in access control lists control all the access to the associated objects from the users or programs that would want to use them. They define who, and at what level can the object or resource be used by entities. It is what controls the overall security in a given system.