The Four Faces of Your Operating System
- service provider
The OS exports commonly needed facilities with standard interfaces, so that programs can be simple and portable.
- executive/bureaucrat/juggler
The OS controls access to hardware, and allocates physical resources (memory, disk, CPU time) for the greatest good.
- caretaker
The OS monitors the hardware and intervenes to resolve exceptional conditions that interrupt smooth operation.
- cop/security guard
The OS mediates access to resources and grants or denies each request.