1. COURSE CODE :: BCOM
11 COURSE ::COMPUTER
APPLICATIONS IN
BUSINESS
Unit -2 :: OPERATING SYSTEMS

2. INTRODUCTION
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An Operating System (OS) is a set of programs that controls
the hardware of a computer and enables it to communicate
and operate with the computer software. As a computer
understands and receives instructions only in machine
language, the OS converts the input and instructions given by
a user into the machine language that can be understood by
the computer, which then processes the data according to the
given instructions to produce the output. The OS again
converts the generated output from machine language to the
high-level language, understandable by the user, before
displaying it on the computer screen.
Apart from coding and decoding instructions, an OS helps to
perform various tasks, such as prioritizing the processes,
performing job scheduling, and managing Central Processing
Unit (CPU) resources in the most efficient manner.

3. OBJECTIVES

Explore about operating system
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Understand the types, features, and functions of operating system

Learn about Windows operating system

Learn about Linux operating system

4. EXPLORING AN OPERATING
SYSTEM

OS is a set of programs that controls and supervises the hardware of a
computer system.

Depending upon the specific tasks and operations that they perform, OS
programs are generally divided into two categories—control and service.

A control program is the main program in most of the OSs and is also
known as monitor, executor, executive, or kernel. Service programs provide
various services to the users of a computer system to perform the required
tasks. Some examples of a service program are language translator and
utility programs.
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Some of the major categories of an OS are as follows:

Single-program OS
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Concurrent OS
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Time-sharing OS
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Multiprocessing OS
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Virtual-storage OS

Real-time OS

5. FUNCTIONS OF AN OS

Processor Management
Processor management refers to task of managing processes (tasks or jobs) allocated to a
processor.

Job Scheduling
Job scheduling, often called process scheduling, is a process of assigning tasks to CPU
according to their priority levels and available resources.

Memory Management
An OS plays an important role in managing the memory of a computer by allocating the portions
of memory to the programs and releasing the unused memory for reusability.

Virtual Storage
Virtual storage is a primary storage that does not actually exist; however, it gives an illusion of the
primary storage to the programmers.

Device Management
An OS manages a device, which is attached to the computer, with the help of an appropriate
driver.

Information Management
In a computer, the OS provides convenient ways for storing and accessing the information from
files.

6. INTRODUCING WINDOWS
OPERATING SYSTEM

The term Windows collectively represents all
Microsoft OS products. Over the years,
Microsoft has released various versions of
Windows Oss, which are as follows:
Windows 95
 Windows 98
 Windows 2000
 Windows XP
 Windows Vista
 Windows 7


7. FEATURES OF WINDOWS OS

Graphical User Interface
GUI is an interface that provides graphical icons to perform various tasks, such as
clicking a folder icon by the user. The main elements of GUI in Windows OS are
pointers, menus, and desktop.

Internet Explorer
Internet Explorer is a Web browser that allows you to search information on the World
Wide Web (WWW).

User Accounts
In Windows, user accounts refer to a collection of information (such as user name and
password) that is used to identify users.

Internet Information Services
IIS is a Web server application that is created by Microsoft to execute Web services or
applications in Windows OS.

System Backup and Restore
The System Backup feature is introduced in Microsoft Windows OS to maintain the back
up of system files, registry keys, and programs.

8. LINUX

Linux is a UNIX-based, freely distributable, and open source OS.
Open source refers to a program whose source code is freely
available on the Internet. This source code is open to
modification by anyone who uses it. The functions performed by
the Linux OS:
 Schedules and prioritizes multiple tasks
 Moves the programs that exceed the available memory to
swap space, which is an area on a hard drive to control the
overflow of the programs
 Supports various hardware devices and also manages the
size of a kernel
 Manages different file system formats, such as Virtual File
Allocation Table (VFAT), NTFS, or ext3
 Provides restricted access to users for working with files and
directories

9. LINUX DISTRIBUTIONS

Linux distributions are the packages consisting of one or
more programs required to perform a single function by the
Linux OS. Some of the most common Linux distribution
packages are as follows:
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Ubuntu
Debian
Gentoo
KNOPPIX
SUSE
openSUSE
Slackware
Mandriva
Freespire
Fedora

10. SUMMARY

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OS is a set of programs that controls and supervises the hardware of a computer
system. Depending upon the specific tasks and operations that they perform, OS
programs are generally divided into two categories—control and service.
A computer includes a wide assortment of I/O devices, called peripheral devices,
such as printers, card readers, magnetic tape units, and magnetic disks. To manage
all these devices, a driver is installed in the computer system. The driver acts as a
translator between the electrical signals of the device and the high-level languages of
OS and application programs.
Job scheduling, often called process scheduling, is a process of assigning tasks to
CPU according to their priority levels and available resources.
Virtual storage is a primary storage that does not actually exist; however, it gives an
illusion of the primary storage to the programmers.
The process of collecting as well as managing information from one or more sources
and then distributing that information to the devices is known as information
management.
Windows 98 is the most popular OS for household works. The most interesting
feature of Windows 98 was the introduction of Universal Serial Bus (USB). USB
facilitates the computers to establish a communication with devices.
Linux is a UNIX-based, freely distributable, and open source OS. Open source refers
to a program whose source code is freely available on the Internet.
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