Windows, Linux, Sun Solaris and Macintosh are no doubt
some of the most popular computer OS. But there are individuals
who have designed their own operating system and they use it on their local
machines. Before we start taking a sneak peek at the operating systems for
computers, let us try to understand what a computer operating system is.
What is
a Computer Operating System?
In simple words, a computer operating system can be said to
be the most important software that runs on a computer. It manages the
computer's memory, processes, and all of its software and hardware. It also
allows you to communicate with the computer without knowing how to speak the
computer's "language". Without an operating system, a computer is
useless. In short, it is more like a foundation to which all other applications
rely on. If you want to run certain software (e.g Application software) in your
computer, it needs to be compatible with the operating system that is running
in your computer.
Now that you have an insight about what is a computer
operating system, let us try to understand the different types of operating
system and their classes.
Types
of Computer Operating Systems
Operating systems can be extensively classified into certain
categories. One thing that needs to be kept in mind is that one particular
operating system can fall into more than one category. The classification is
based on the features that operating system possess.
Operating
systems can be classified as follows:
Multithreading
OS
These are the operating systems that allow different parts
of the same software to run concurrently. Operating systems like Windows 9X,
ME, XP, Vista, 7 and Linux are examples of this type of operating system.
Multitasking
OS
This kind of operating system allows more than one program
to run concurrently.
GUI OS
GUI stands for Graphical User Interface. Those operating
systems like Windows 98, XP, ME, Vista, 7 and Linux, which allow users to
navigate with the help of a mouse and have graphic representation of every
process or application are classified into this type of operating system.
Multiprocessing
OS
This operating system supports running a program on more
than one CPU.
Multi-user
OS
Operating systems which allow more than one user to log in
to the computer system at the same time and use it, can be classified as
multi-user operating system. Linux is an example of this type of operating
system, which allows six users to login at the same time and user the operating
system.
Real
time OS
Responds to input instantly. General-purpose operating
systems, such as DOSS and UNIX, are not real-time.
Features
of an Operating System
- Managing Hardware and Software
As already mentioned, it is the computer operating system
that causes the hardware and software in a computer to interact with each
other. It is also the platform that causes one software in the computer to
communicate with another. Once the operating system in a computer loads during
the booting up process, other application software can be loaded into the
computer.
- Consistent Application Program Interface
Application Program Interface which software development
professionals refer to as APIs allow the applications that runs on one computer
to run on another computer having the same operating system. It is thus
important that the operating system has a consistent API. Undoubtedly, every
operating system will have certain requirements, but it should be flexible
enough to support computer hardware from different vendors.
- Program Execution
It is up to the operating system to execute all the programs
running in it. It is a rather complicated process. It may have to allow
multitasking and allow different programs to run at the same time and share the
system resources. It needs to allot RAM space to different applications running
on the computer. The execution of more than one program may also require the
operating system to prioritize the operations running on the computer.
- Interrupts
The operating system needs to support a good number of
interrupts to react with the immediate external environment. On receiving an
interrupt it should have the capability to stop the current execution and start
off a new process. Interrupting is not a very simple process. On receiving an
interrupt, the computer operating system should be such that they immediately
save the status of the current applications and start executing the code of
that particular interrupt.
- Memory Management
As already mentioned in the section on program execution, it
is up to the computer operating system to provide memory to the different
programs running on the computer. It has to prioritize and allocate memory to
each application. Even when data is saved in a secondary storage device, it is
the operating system that decides how that particular chunk of information
should be stored.
- Accessing Data
The data required by any particular application software for
its smooth running needs to be accessed by the operating system. The operating
system stores data in a particular storage area in such a way that the data can
be retrieved as and when required. The file system that different computers use
may be different. The operating system needs to support these different file
systems. Let us try to understand this with an example. Some computers may be
using the FAT 32 file system, while some may be using the NTFS file system.
Irrespective of which file system is being used, the operating system should
provide support for the same. However, not all operating systems support all
types of file systems.
- Networking
We are in the age of networking. Computers need to
communicate with each other. A computer without Internet is not even
imaginable. It is the task of the operating system to provide the required
networking features. It should have features to allow two or more computers to
connect and form a network or connect to the Internet.
- Security
Last but not the least, in today's age, security that an
operating system should provide is undoubtedly one of its most important
features. Right from setting passwords for logging in, to providing firewall
protection; everything comes under the tasks of an operating system. Some
network utilities may need file sharing, printer sharing and using TCP/IP
protocols. Hence, it becomes very important for the computer operating system
to provide proper security so that the computer's security is not compromised
in such cases.
Now let’s take a look at the details of the different
operating systems available in the market. Here, we will take a look at only
the most popular operating systems and of course, these are the operating systems
which you would want to know about.
Best
Operating Systems
- Unix-like
Operating Systems
We are all aware of the fact that Unix is an open source
operating system. By open source, we mean that its source code is kept free for
changes. No doubt, for a full version Linux, you will need to have the license
key from the vendor from whom you are getting the operating system. There are
various vendors like Red Hat, Fedora, etc. who design Linux operating system.
History
of Unix
Unix operating system is designed by many vendors today.
However, the success of Unix can be attributed to the AT&T's Bell
Laboratories from where it was released in the early 1970s. By the end of the
1970s most people who had done pioneering work in the success of this operating
system were holding important positions in the computer world. They insisted on
using Unix. Government bodies, educational institutions and electronic
companies, all continued to use Unix. This led to various vendors entering into
this market and producing their own versions of Unix. In 1980, 'The Open Group'
or X/Open Company Ltd. was formed by a group of vendors to limit the
encroachment by larger companies who wanted to control the system interface.
Open Systems had to meed specific standards and Unix system was chosen as the
platform for the open systems. In 1993, AT&T sold its Unix System
Laboratories to Novell and in 1995, SCO bought the same from Novell. In 1995
X/Open introduced the Unix 95 brand for computer systems. It was meant to
guarantee the Single Unix specification.
- Microsoft
Disk Operating System (MSDOS)
It is the operating system, which probably marks the rise of
Microsoft. DOS is another operating system which has the basic feature of CUI
(Character User Interface) mode. You need to learn the commands. Undoubtedly,
it was one of the most powerful operating systems of its time and Microsoft
continuously tweaked and improved this product, which led them to capture a
significant market.
History of MSDOS
The original version of DOS, QDOS was purchased by Microsoft
from Seattle Computer Products in 1981. Microsoft kept on improving this
product and by 1984, they had added support for high density floppy disks, 32
MB hard disks and networking. Microsoft continued to release different versions
of DOS and worked on the bugs present in those versions. By 1993, Microsoft had
included the MOVE command, MSBACKUP and a simple anti-virus program and disk
defragmenter. In 1994, Microsoft licensed a disk compression package called
DriveSpace and included it in its DOS version. This version is also a part of
the Windows 95 operating system.
- Macintosh
Macintosh is the line of operating systems, developed and
marketed by Apple Inc. It is the primary operating system of Apple Computers
right from 1984. It is a Unix based operating system. This operating system is
often credited for the start of the graphical user interface systems.
History of MAC OS
Starting in early 1979, the Macintosh project was meant to
build an operating system that will be easy to use for the average user. Unlike
the IBM PC which used 8KB of system ROM for power on self test (POST) MAC ROM
was larger (64 KB). The first version of Macintosh was an easy contrast from
the operating systems of that time. Users no longer had to type commands. Newer
versions of Macintosh were launched and it still holds a great graphical user
interface system. The latest version in MAC OS X 10.6 (Snow Leopard).
- Microsoft
Windows
Here I am referring to the Windows operating system. It is
the most widely used operating system in the world and again a product from
Microsoft. The latest version is Microsoft Windows 7. Microsoft Windows was an
operating system that included support for a variety of features before other
operating systems had included them. The large market that they captured led to
the production of a wide range of software specifically meant for the Windows
operating system.
History of Microsoft Windows
In November 10, 1983, Microsoft announced the launch of
Microsoft Windows, which was nothing but an extension of the MS DOS operating
system. This marked the beginning of the GUI era. The success that they saw
caused them to work upon newer versions of Windows. Windows 95 was acclaimed to
a greater extent when it was released in 1995. The year 2000 saw the release of
Windows ME after Windows 98 in 1998 and finally there was Windows XP, which was
released in the year 2001. All these operating systems included a variety of
features. There was constant improvement with each version and the GUI got
better and better. The year 2006 saw the release of Windows Vista with an even
better graphical interface as compared to Windows XP, but it did have its own
drawbacks. Finally Microsoft brought Windows 7 to the markets in March 2010,
and most of the problems with Windows Vista were fixed.
Which
Operating System to Choose?
Well, it all depends on type of work you intend to do. There
are various other factors that you need to consider. If you are into computer
administration, learning how to use Unix based operating systems will
definitely prove helpful to you. For a common man, the best operating system is
one, which is easy to use. It is also important to find out whether software
manufacturers provide versions that are compatible with your computer operating
system. All other features that have been mentioned above should form the basis
of your choice of your computer operating system. Also check for features like
network support and character set support when using an operating system. They
may not be important for everyone, but these features are of considerable
importance for specific kind of jobs.
There are many other operating systems other than the aforementioned,
but I have tried to mention the ones we most commonly hear about. The computer
operating system is the heart of a computer, so choose one for your computer
wisely.
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