Operating Systems: Operating system classifications

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UNIT 3 - ⇑ Operating Systems ⇑

← Resource management Operating system classifications

Operating System Classification/Types of Operating Systems[edit]


In an interactive operating system, the user interacts directly with the operating system to supply commands and data as the application program executes and the user receives the results of processing immediately. The user is in direct two way communication with the computer.

Example: An ATM machine.

Real time[edit]

A real time operating system will give guaranteed feedback within a predefined set period of time, therefore taking away the unpredictability of the operation being carried out. This allows for the system to be mathematically modelled to allow the time needed for operations to be carried out to be determined, even under the predicted maximum stress levels. It allows deadlines to be set on operations being carried so as to provide a "best of" result within the time period able to be given for an operation.

Example: If a real time operating system was used to control a planes rudders (via a RT application) it would need to set deadlines on the calculations used to calculate rudder movements. Without these deadlines a calculations results may be returned to late and cause to plane to crash.

One very important factor to remember about real time operating systems and applications is that "the right answer late is wrong". After all what is the point in having the correct answer to a planes rudder calculation if it comes too late and the plane has already crashed because the rudder angle was not changed earlier.


A layer of software is added to the operating system of a computer connected to the network. This layer intercepts commands that reference resources elsewhere on the network, e.g. a file server, then redirects the request to the remote resource in a manner completely transparent to the user.



A dedicated computer system with a limited or non-existent user interface and designed to operate completely or largely autonomously from within other machinery.


An operating system that allows a user to carry out a broad range of general-purpose tasks.


Server Operating System is an operating system that provides its networked clients some specific services.

Server Operating system doesn't have GUI because:

  • more expensive as it costs more money
  • it takes up processing power

Client-server System is a system where services are requested by clients and these services are provided by other computers.