Operating system

##AN INTRODUCTION TO OPERATING SYSTEMS 
1.Application software performs specific task for the user. 
2.System software operates and controls the computer system and provides a platform to run application software. 
An operating system is a piece of software that manages all the resources of a computer system,both  hardware  and  software,  and  provides  an  environment  in  which  the  user  can  execute  his/her programs in a convenient and efficient manner by  hiding  underlying  complexity of the hardware and acting as a resource manager. 
#Why OS? 
1. What if there is no OS? 
a. Bulky  and  complex  app.  (Hardware  interaction  code  must be  in  app’s code base) 
b. Resource exploitation by 1 App. 
c. No memory protection. 
2. What is an OS made up of? 
a. Collection of system software. 
An operating system function - 
- Access to the computer hardware. 
- interface between the user and the computer hardware 
- Resource management (Aka, Arbitration) (memory, device, file, security, process etc) - Hides the underlying complexity of the hardware. (Aka, Abstraction) - facilitates execution of application programs by providing isolation and protection. 
The operating system provides the means for proper use of the resources in the operation of  the computer system.