An operating system is

• a software that manages a computer’s hardware.

It also provides a basis for application programs and

• acts as an intermediary between
• the computer user and the computer hardware.

A computer system can be divided roughly into four components:

• the hardware

• the operating system

• the application programs

• and a user

  

  • 컴퓨터 하드웨어가 있으면 거기에 Opertating system이라는 추상적인 layer가 있어서 system and application programs이 operating system과 통신을 하면 hardware를 transparent하게 프로그래밍을 할 수 있다.

Defining Operating Systems

• There are no universally accepted definition of an operating system.
• A more common definition is that
  • the one program running at all times on the computer
  • usually called the kernel.
• Along with the kernel, there are two other types of programs:
  • system programs
  • application prgrams
• Kernel이 OS의 Core한 부분을 담당하게 된다.