What is discretionary control?

In discretionary control, a given user will typically have different access rights on different objects. Different users will typically have different rights on the same object. Discretionary schemes are, thus, flexible. Discretionary control can be compared with the access control in the UNIX operating system. In UNIX file system, access permissions of user, group and others (ugo) are associated with each file. All three (ugo) has the combination of read, write and execute permission on the file.