Generally, operating systems are separated into Unix and non-Unix.
Some examples:
Unix:
There are basically four types of operating systems. They include Batch Operating System, Multiprogramming Operating System, Network Operating System and Distributed Operating System.
There are two types of OS as follow:- Desktop Operating System- Network Operating System
Main Types of operating system are WindowsMac OSLinuxSun Solaris
Jobs with similar needs are batched together and run through the computer as a group.
operating system is a control program as it allow multiple task to performed on same window.
What exactly do you mean by 'optimal operating system'? If you don't define the term there is no way to answer the question.
types of devices in operating system
DOS is short for disk operating system.
User Rights
States define an exact operating condition of a system, where modes define the set of capabilities or functions which are valid for the current operating condition. (Source: http://themanagersguide.blogspot.com.au/2011/01/6322-define-life-cycle-system-modes.html)
Firmware, Operating System, and Utilities.
Operating system software .....OPERATES !! and utility software....UTILIZES !! ..now go do your research .