Discretionary Access Control (DAC) is one of the classic access control models. The others are Mandatory Access Control( MAC), Role-Based Access Control( RBAC) and Attribute-Based Access Control( ABAC).
Discretionary Access Control (DAC) depends on the user and is based on the existing access rules. The access rules contain the policies for the requester and his activity. The requester is allowed to perform only those activities that are specified in the policies. The system administrator can expand and restrict the access options and their use that are listed in the Discretionary Access Control List( DACL).