An Operating System is the interface between the computer hardware and the end-user . Processing of data, running applications, file management and handling the memory is all managed by the computer OS. Windows, Mac, Android etc. Are examples of operating systems which are generally used nowadays. Operating System Tutorial provides the basic and advanced concepts of operating system . Our Operating system tutorial is designed for beginners, professionals and GATE aspirants. We have designed this tutorial after the completion of a deep research about every concept. The content is described in detailed manner and has the ability to answer most of your queries. The tutorial also contains the numerical examples based on previous year GATE questions which will help you to address the problems in a practical manner. Operating System can be defined as an interface between user and the hardware. It provides an environment to the user so that, the user can perform its task in convenient and efficient way. The Operating System Tutorial is divided into various parts based on its functions such as Process Management, Process Synchronization, Deadlocks and File Management. n the Computer System (comprises of Hardware and software), Hardware can only understand machine code (in the form of 0 and 1) which doesn't make any sense to a naive user. We need a system which can act as an intermediary and manage all the processes and resources present in the system.An Operating System can be defined as an interface between user and hardware. It is responsible for the execution of all the processes, Resource Allocation, CPU management, File Management and many other tasks. The purpose of an operating system is to provide an environment in which a user can execute programs in convenient and efficient manner.A Program does nothing unless its instructions are executed by a CPU. A program in execution is called a process. In order to accomplish its task, process needs the computer resources. There may exist more than one process in the system which may require the same resource at the same time. Therefore, the operating system has to manage all the processes and the resources in a convenient and efficient way. Some resources may need to be executed by one process at one time to maintain the consistency otherwise the system can become inconsistent and deadlock may occur. The operating system is responsible for the following activities in connection with Process Management Scheduling processes and threads on the CPUs. Creating and deleting both user and system processes. Suspending and resuming processes. Providing mechanisms for process synchronization. Providing mechanisms for process communication. Next TopicAttributes of a Process ← PrevNext → Youtube For Videos Join Our Youtube Channel: Join Now Feedback Send your Feedback to feedback@javatpoint.com Help Others, Please Share facebook twitter pinterest Learn Latest Tutorials Splunk tutorial Splunk SPSS tuto

1. An Introduction to
Operating Systems

2. Definition
 An Operating System, or
OS, is low-level software
that enables a user and
higher-level application
software to interact with a
computer’s hardware and
the data and other
programs stored on the
computer.
 An OS performs basic
tasks, such as recognizing
input from the keyboard,
sending output to the
display screen, keeping
track of files and directories
on the disk, and controlling
peripheral devices such as
printers.

3. Other Services
 Program Execution
OS provides an environment where the user can conveniently run
programs. The user does not have to worry about memory allocation
or CPU scheduling.
 I/O Operations
Each program requires input and produces output. The OS hides
some of the details of the underlying hardware for such I/O. All the
user sees is that the I/O has been performed, without those details.
 Communications
There are instances where processes need to communicate with
each other to exchange information. It may be between processes
running on the same computer or running on different computers.
The OS provides these services to application programs, making
inter-process communication possible, and relieving the user of
having to worry about how this accomplished.

4. Application programs and OS
 Operating systems provide a software platform on top of which other
programs, called application programs, can run.
 The choice of operating system, therefore, determines to a great
extent the applications a user can run.
 For example, the DOS operating system contains commands such
as COPY and RENAME for copying files and changing the names of
files, respectively. The commands are accepted and executed by a
part of the operating system.
 Similarly, the UNIX operating system has commands like CP and
MV to copy and rename.

5. UNIX
 UNIX was one of the first operating systems
to be written, in 1971.
 Advantages of UNIX are…
 Multitasking – multiple programs can run at
one time.
 Multi-user – allows more than a single user
to work at any given time. This is
accomplished by sharing processing time
between each user.
 Safe – prevents one program from
accessing memory or storage space
allocated to another program, and enables
file protection, requiring users to have
permission to perform certain functions,
such as accessing a directory, file, or disk
drive.

6. Types of OS
 Microsoft Windows
 Mainframe
 DOS
 OS/2
 Linux
 Mac OS
 AmigaOS

7. Types Of OS

8. Evolution of Windows

9. Evolution of OS/2