A program that acts as an intermediary between a user of a computer and the computer hardware.
Operating system goals:
Provide environment in which user can execute programs and make solving user problems easier.
Make the computer system convenient to use. Use the computer hardware in an efficient manner.
Computer System Components
1. Hardware – provides basic computing resources (CPU, memory, I/ O devices).
2. Operating system – controls and coordinates the use of the hardware among the various application
programs for the various users.
3. Applications programs – define the ways in which the system resources are used to solve the
computing problems of the users (compilers, database systems, video games, business programs).
4. Users (people, machines, other computers).
Abstract View of System Components
Operating System Definitions
Resource allocator – manages and allocates resources.
Control program – controls the execution of user
Programs and operations of I/ O devices .
Kernel – the one program running at all times (all else being application programs).