PROTECTION SYSTEM:
Protection is any mechanism for controlling the access of programs, processors are users to the resources defined by a computer system. This mechanism for must provide means for specification of the controls to be impossed and means for enforcement.
Protection can improve reliability by detecting latend errors at the interfaces between components of system. Early detection of interface errors can aften prevent contamination of a healthy sub system by another sub system that is malfunctioning. An unprotect resources cannot defined against to use by an unauthoriside are incompetent user.