The document discusses the functions of an operating system. It begins by defining an operating system as software that manages computer hardware and provides an interface between users and programs. It then describes the boot process, where the BIOS activates and checks hardware, loads the master boot record to start the operating system. Finally, it lists the main services an operating system provides, such as managing processes, memory, devices, files, security, and networks.

1. Dayan sir 0714146866 GCE(A/L)-ICT-GIT
UDAYA K. DAYAN (Government SLICT-Service)
GEC (A/L) – ict/GIT
An operating system acts as an intermediary between the user of a computer and computer
hardware. The purpose of an operating system is to provide an environment in which a user can execute
programs in a convenient and efficient manner.
Definition: An operating system is a software that manages the computer hardware. The hardware must
provide appropriate mechanisms to ensure the correct operation of the computer system and to prevent user
programs from interfering with the proper operation of the system.
How the initial operations of a computer are performed
 When the user powers up the computer the CPU (Central Processing Unit) activates
the BIOS (Basic Input Output System).
 The first program activated is POST (Power On Self-Test). Using the CMOS
(Complementary Metal Oxide Semiconductor) memory this checks all the hardware
and confirms that all are functioning properly.
 After that it reads the MBR (Master Boot Record) in boot drive in accordance with the
firmware ‘bootstrap loader’ which is provided by the computer manufacturer.
 Then the computer loads in the Operating System in boot drive to the RAM (Random
Access Memory)
 Once this is performed the Operating System takes over the control of the computer
and displays a user interface to the user.
This whole process is called booting which means that an Operating System is
loaded into the RAM (main memory).

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Types of Operating Systems

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4. Dayan sir 0714146866 GCE(A/L)-ICT-GIT
Services of an Operating System
The Operating System is a software which manages the hardware and other
software in a computer system. It provides services to other software. There are
two main services performed by an operating system. They are:
1. Managing the hardware of a computer
2. Providing user interface
1) Managing the Hardware of a computer Hardware of a computer are managed
by using the following processes;
i. Process Management
ii. Memory Management
iii. Device Management
iv. File Management
v. Security Management
vi. Network Management

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6. Dayan sir 0714146866 GCE(A/L)-ICT-GIT
Why do we need partitioning? …………………………………………………………
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To view these data,
Right click on a particular file
And then click on
‘Properties’ from the list that appears.

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