Good Explanation on OS

2.  This Presentation would cover-
 What is an Operating system?
 Features of Operating System
 Uses of Operating System
 Types of Operating System

3. 3
i)
WHAT IS AN OPERATING SYSTEM?
 An interface between users and hardware- an environment "architecture”
 Allows convenient usage; hides the tedious stuff
 Allows efficient usage; parallel activity, avoids wasted cycles
 Provides information protection
 Gives each user a slice of the resources
 Acts as a control program.
OPERATING SYSTEM

4. I]Scheduling
The task of handling how active processes are making efficient
use of the CPU processing cycles is called scheduling. There are
many ways of doing this, which is covered in another mini-
website.
II]Memory Management
The operating system has to make sure that applications are
able to run in the amount of memory available and that they do
not interfere with one another. There is a separate mini-website
on this topic.

5. III]Allocation of resources
The operating system will provide a working area for
each user. This includes-
 Disk space quota for their files ( especially on shared
network drives)
 A personal GUI set up for each user (multi-user
operating systems)
 Perhaps how many processing cycles they are
allowed to use (especially on mainframe)
 How much printer output they are allowed
(networked and mainframe)
 How high a priority they can assign to a job
(mainframe)

6.  The main use of an operating system is to ensure that a
computer can be used and do exactly what the user wants it
to, the commands that are given by the user need to be
understood by the operating system that is in place do the
computer or device can act accordingly. The ability to have
one single operating system makes everything much easier as
there don't have to be too many different processes for the
technology to do what it is told.
 Problems can be avoided and taken care of as quickly as
possible with an operating system as it can control
everything. It is simple, if there wasn't an operating system in
place with all different types of technology, and then they
would not work as they are supposed to and therefore
technology would not have advanced as much as it
currently has.

7. .All you need to know is that the necessity of having an
operating system is very important and you would not be able to
have the technology working as you wanted it to without the
system in place. Resources and documents are also taken care
of by the system so there are going to be no problems when it
comes to keep important documents and using them when you
need to. You can keep many different resources and be sure
that the operating system will ensure that they are not going to
be removed by the device unless you tell it to.
.With an operating system you can be in complete control
without any worries of the technology failing you. Without and
operating system all of the computers and devices that we have
would not be as resourceful or as reliable as they currently are in
today's society.

8.  Real-time
A real-time operating system is a multitasking operating system that
aims at executing real-time applications. Real-time operating
systems often use specialized scheduling algorithms so that they
can achieve a deterministic nature of behavior. The main objective
of real-time operating systems is their quick and predictable
response to events. They have an event-driven or time-sharing
design and often aspects of both. An event-driven system switches
between tasks based on their priorities or external events while time-
sharing operating systems switch tasks based on clock interrupts.
 Multi-user
A multi-user operating system allows multiple users to access a
computer system at the same time. Time-sharing systems and
Internet servers can be classified as multi-user systems as they
enable multiple-user access to a computer through the sharing of
time. Single-user operating systems have only one user but may
allow multiple programs to run at the same time.

9.  Multi-tasking vs. single-tasking
A multi-tasking operating system allows more than one
program to be running at the same time, from the point
of view of human time scales. A single-tasking system
has only one running program. Multi-tasking can be of
two types: pre-emptive and co-operative. In pre-
emptive multitasking, the operating system slices the
CPU time and dedicates one slot to each of the
programs. Unix-like operating systems such as Solaris and
Linux support pre-emptive multitasking, as
does AmigaOS. Cooperative multitasking is achieved by
relying on each process to give time to the other
processes in a defined manner. 16-bit versions of
Microsoft Windows used cooperative multi-tasking. 32-
bitversions of both Windows NT and Win9x, used pre-
emptive multi-tasking. Mac OS prior to OS X used to
support cooperative multitasking.

10.  Distributed
A distributed operating system manages a group of independent
computers and makes them appear to be a single computer. The
development of networked computers that could be linked and
communicate with each other gave rise to distributed computing.
Distributed computations are carried out on more than one machine. When
computers in a group work in cooperation, they make a distributed system.
 Templated
In an o/s, distributed and cloud computing context, templating refers to
creating a single virtual machine image as a guest operating system, then
saving it as a tool for multiple running virtual machines (Gagne, 2012, p.
716). The technique is used both in virtualization and cloud computing
management, and is common in large server warehouses. [4]
 Embedded
Embedded operating systems are designed to be used in embedded
computer systems. They are designed to operate on small machines like
PDAs with less autonomy. They are able to operate with a limited number of
resources. They are very compact and extremely efficient by design.
Windows CE and Minix 3 are some examples of embedded operating

11. 1: Operating Systems Overview 11
The Layers Of
A System
Program
Interface
Humans
User Programs
O.S. Interface
O.S.
Hardware Interface/
Privileged
Instructions
Disk/Memory/Scree
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