Question

Compare and contrast os,dos ,nos and middleware

Answer 1

Parameters

Network Operating System (NOS)

Distributed Operating System (DOS)

1. Definition

A network operating system (NOS) is a computer operating system that is designed primarily to support workstation, personal computer, and, in some instances,older terminal that are connected on a local area network.

An operating system which manages a number of computers and hardware devices which make up a distributed system.

2. Goal

The main goal is to offer local services to remote clients.

The main goal is to hide and manage hardware resources.

3. Used for

It is a loosely coupled operating system for heterogeneous multi-computers

It is a tightly-coupled operating system for multi processor and homogeneous multi-computers.

4. Architecture

Network OS follows 2 tier Client server architecture

Distributed OS follows n tier client/server architecture

5. Types

Two types of DOS- multi computer operating system and multiprocessor operating system.

Two types of NOS-,Peer-to-peer and client/server architecture.

6. Communication

NOS uses files for communication

DOS uses messages for communication

7. Transparency

Degree of Transparency is low

Degree of Transparency is high

8. Example

Novell NetWare

Microsoft-Distributed Component Object Model(

Answer 2

Operating system:

• An operating system is system software that copes computer hardware, software resources, and offers common services for computer programs.

• A DOS is a computer operating system that can use a disk storage device, like a floppy disk, hard disk drive, or optical disc.  

• Middleware is computer software that offers services to software applications afar those accessible from the OS.