• Consists of Kernel and OS System Program
  • 2 main functionalities
    1. Provide user like you and me features to interact with the hardware like browsing the web
    2. Resource Manager for resources like IO Device & Main Memory etc

Types of OS

Embedded OS

  • Run on devices like ovens, no un-trusted software will ever run on it
  • All software in ROM
  • One example is OpenWRT

Smart Card OS

Server OS

Sensor-Node OS

Real-Time OS

Personal Computer OS

  • Support Multi-programming - dozens of programs started up at boot time
  • Provide good support to a single user
  • Widely used for word processing, spreadsheets & gaming etc
  • Example are Linux Kernel and Windows

Handheld Computer OS

Mainframe OS

Multi-processor OS


Batch System

  • Process jobs without any interactive user present

Transaction-processing System

  • Handle large number of of small requests, hundreds/thousands per second