2. TABLEOFCONTENTS
• Introduction
• Operating System
• History of Operating System
• Types of Operating System
• Some Popular Operating Systems
• Features Of Operating System
• Limitations of OS
• References
2
3. Introduction
• Operating System is a software that makes a computer to
actually work.
• It enables us all the programs we use.
• An operating system acts as an intermediary between the
user of a computer, applications and computer hardware.
• OS also the means of communication between various
Hardwares.
3
4. OperatingSystem
• An operating system (OS) is the program that, after being
initially loaded into the computer by a boot program.
• The application programs make use of the operating system by
making requests for services through a de
fi
ned application
program interface (API).
• These requests/commands further executed through hardwares
with the help of kernel.
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5. OperatingSystem
• Resource Management: When parallel accessing happens in
the OS means when multiple users are accessing the system the
OS works as Resource Manager, Its responsibility is to provide
hardware to the user. It decreases the load in the system.
• Process Management: It includes various tasks like scheduling
and termination of the process. It is done with the help of CPU
Scheduling algorithms.
• Storage Management: The
fi
le system mechanism used for the
management of the storage. NTFS, HSF, etc. are some le
systems. All the data is stored in various tracks of Hard disks that
are all managed by the storage manager. It included Hard Disk.
Functions Of Operating System
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6. OperatingSystem
Functions Of Operating Systems
• Memory Management: Refers to the management of primary
memory. The operating system has to keep track of how much
memory has been used and by whom. It has to decide which process
needs memory space and how much. OS also has to allocate and
deallocate the memory space.
• Security/Privacy Management: Privacy is also provided by the
Operating system by means of passwords so that unauthorized
applications can’t access programs or data. For example, Windows
uses Kerberos authentication to prevent unauthorized access to data.
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7. Operating System
How Operating System Works?
• User Interface:The user interface accepts commands to execute programs and
use resources and services provided by the operating system.It is of Two types:
i)CLI(Command Line Interface):Unix,Linux
ii)GUI(Graphical User Interface):Windows,Macintosh(MacOS)
• Non-Kernel Routines: These routines implement user commands concerning
execution of programs and use of the computer’s resources; they are invoked by
the user interface.
• Kernel: The kernel is the core of the OS. It controls operation of the computer
and provides a set of functions and services to use the CPU, memory, and other
resources of the computer.
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8. •The
fi
rst computer, Z1, was made in 1936 – 1938. Unfortunately, this computer
ran without an operating system.
•Twenty years later, the
fi
rst-ever operating system was made in 1956 i.e Batch
OS.
•In the 1960s, bell labs started working on building UNIX, the rst multitasking
operating system.
•In 1977 the apple series came into existence. Apple Dos 3.3 was the rst disk
operating system.
•In 1981, Microsoft built the
fi
rst operating system called DOS by purchasing 86
– DOS software from a Seattle company.
•The most famous Microsoft windows came into existence in 1985 when MS-
DOS was paired with GUI, a graphics environment.
HistoryofOperatingSystem
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9. TypesofOperatingSystem
Batch Operating System
• In Batch OS similar types of jobs were batched together and executed in time.
People were used to having a single computer which was called a mainframe
• Access is given to more than one person; they submit their respective jobs to
the system for the execution.
• The system put all of the jobs in a queue on the basis of rst come rst serve
and then executes the jobs one by one. The users collect their respective
output when all the jobs get executed.
• It contained a small set of programs called the resident monitor that always
resided in one part of the main memory. The remaining part is used for
servicing jobs
• Advantage:it eliminates CPU time between two jobs.
• Disadvantage:Su
ff
er from Starvation
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10. TypesofOperatingSystem
MultiProgramming Operating System
•Multiprogramming is an extension to batch processing where the
CPU is always kept busy. Each process needs two types of system
time: CPU time and IO time.
•when a process does its I/O, The CPU can start the execution of
other processes. Therefore, multiprogramming improves the
e
ffi
ciency of the system.
•Advantages: Throughput the system is increased as the CPU
always had one program to execute.
•Response time can also be reduced.
•DisAdvantages:do not provide any user interaction with the
computer system.
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11. TypesofOperatingSystem
MultiProcessing Operating System
• More than one processors present in the system which can execute more than
one process at the same time.
• In Multiprocessing, Parallel computing is achieved.
• Advantages:
1. Increased reliability: Due to the multiprocessing system, processing tasks can
be distributed among several processors. This increases reliability as if one
processor fails, the task can be given to another processor for completion.
2. Increased throughput: As several processors increase, more work can be
done in less.
• DisAdvantages:
1. More complex and sophisticated as it takes care of multiple CPUs
simultaneously.
2. Costly
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12. TypesofOperatingSystem
MultiTasking Operating System
• The multitasking operating system is a logical extension of a
multiprogramming system that enables multiple programs
simultaneously.
• It allows a user to perform more than one computer task at the same
time.
• Advantages:
1. This operating system is more suited to supporting multiple users
simultaneously.
2. The multitasking operating systems have well-de
fi
ned memory
management.
• DisAdvantages:
1. The multiple processors are busier at the same time to complete any
task in a multitasking environment, so the CPU generates more heat
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13. TypesofOperatingSystem
Network Operating System
•Network Operating System includes software and associated protocols
to communicate with other computers via a network
• allow sharing of various
fi
les, applications, printers, security, and other
networking functions over a small network of computers like LAN or any
other private network.
•In the network OS, all the users are aware of the con
fi
gurations of every
other user within the network
•Advantages:
1. New technologies and hardware can easily upgrade the systems.
2. Security of the system is managed over servers.
3. The centralized servers are stable.
•Disadvantages:
1. Server costs are high.
2. Regular updates and maintenance are required.
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14. TypesofOperatingSystem
Distributed Operating System
•Distributed Operating system is not installed on a single machine, it is divided into
parts, and these parts are loaded on di
ff
erent machines.
• In a distributed OS, various computers are connected through a single
communication channel.
•These independent computers have their memory unit and CPU and are known as
loosely coupled systems
•The system processes can be of di
ff
erent sizes and can perform di erent functions.
•Advantages:
1. Failure of one system will not a
ff
ect the other systems because all the computers
are independent of each other.
2. The load on the host system is reduced.
•DisAdvantages:
1. The setup cost is high.
2. Software used for such systems is highly complex.
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15. TypesofOperatingSystem
Real Time Operating System
•In Real-Time Systems, each job carries a certain deadline within which the job is
supposed to be completed
•The Application of a Real-Time system exists in the case of military
applications, if you want to drop a missile, then the missile is supposed to be
dropped with a certain precision
•Advantages:
1. It provides more output from all the resources as there is maximum
utilization of systems.
2. It provides the best management of memory allocation.
3. These systems are always error-free.
•DisAdvantages:
1. System resources are extremely expensive and are not so good.
2. The algorithms used are very complex.
3. Only limited tasks can run at a single time.
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17. FeaturesofOS
• It is helpful to monitor and regulate resources.
• It can easily operate since it has a basic graphical user interface
to communicate with your device.
• It is used to create interaction between the users and the
computer application or hardware.
• The performance of the computer system is based on the CPU.
• The response time and throughput time of any process or
program are fast.
• It can share di
ff
erent resources like fax, printer, etc.
• It also o
ff
ers a forum for various types of applications like
system and web application.
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18. LimitationsofOS
• It allows only a few tasks that can run at the same time.
• It any error occurred in the operating system; the stored data can be
destroyed.
• It is a very di
ffi
cult task or works for the OS to provide entire security
from the viruses because any threat or virus can occur at any time in a
system.
• An unknown user can easily use any system without the permission of
the original user.
• The cost of operating system costs is very high.
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