What is the Operating System?

OS is a Resource Allocator

• Manages all resources

• Decides between conflicting requests

OS is a Control Program

• Controls the execution of programs to prevent errors and improper use of the machine

A system is divided into 4 parts:

1. Hardware
   1. provides basic computing resources
   2. CPU, Memory, I/O devices...

2. Operating system
   1. Controls the hardware, coordinates use of hardware among various applications and the users

3. Application Programs
   1. defines the way how computer resources can be used to solve the problems of the user
   2. Word processors, calculator...

4. Users
   1. pretty obvious what they are... other machines and humans