foil on Section 2.4
* manage resources
allocates processors, memory, disk storage
responds to events associated with resources
* service to clients
creates a high level interface - virtual resources
(virtual processors, virtual memory,
virtual devices, virtual storage (files) )
TRADEOFF:
resource utilisation (throughput)
vs
fairness to all users
Operating system interfaces
* set of commands
to create and compose processes
* set of system calls