Discretionary Access Control (DAC) or user dictated access control.
This includes both classic UNIX style permission checks and POSIX Access Control Lists (ACL).
Classical UNIX checks compare the current process UID and GIDversus(درمقابل) the UID and GID of the file being accessed with regards(با احترام) to which modes have been set (Read/Write/eXecute).
Access Control List extends classic UNIX checks to allow more options regarding permission control