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Application Software
System Software
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Performs specific tasks and works on top of
the operating system.
Three main types
◦ General Purpose
◦ Special Purpose
◦ Custom Written
APPLICATION SOFTWARE
OPERATING SYSTEM
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Software that performs basic tasks that most
users would need to do. Comes in a software
suite or Integrated software.
Eg. Microsoft Office, PDF reader, Adobe
Photoshop
ADVANTAGES
Relatively Cheap
Easy to learn
No compatibility issues
Easy to Install
DISADVANTAGES
Little or no
Customization
Comes in a package and
cannot be separated
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Software designed to perform a specific task.
Eg. Accounting, Engineering Design, Music
player.
ADVANTAGES
Meets a specific need
DISADVANTAGES
Can be expensive
Usually integrates with
other software well
Has no other use other
than what it was made for.
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Software that is designed specifically for an
organization to meet their individual needs.
Eg. Government databases, Large businesses.
ADVANTAGES
DISADVANTAGES
Meets the individual needs Very costly
of the user
Can be modified to meet
new needs
Difficult to troubleshoot at
times
Cannot be used for
anything else.
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They enable the computer to run properly.
Application programs depend on the System
software to run.
There are 2 main types
OS (Operating System)
Utilities
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The operating system is the set of programs
that controls all the hardware and application
programs that make up the computer system.
They are the most important programs
because every other program depends on it.
Eg.
◦ PC-Windows, Linux, UNIX, Mac OS, DOS
◦ Phone -Android, iOS, Symbian, Windows Mobile
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Process Management
◦ Allotting adequate time and resources to each
process/program
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File Management
◦ Provides the ability to modify files and folders while
keeping track of their physical location on the hard
drive.
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Memory Management
◦ Manages the memory the computer has so that
every program can get to load as quickly and
efficiently as possible.
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Input/Output Management
◦ Controls the communication with external hardware
like keyboard, mouse, printers, monitor etc…
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Security and Maintenance
◦ Provides some level of security to ensure the
software is safe from viruses and malware. Provides
utilities to ensure backups and error corrections
take place.
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User Interface
◦ Provides a user interface that the user can interact
with to give inputs.
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THREE TYPES
Command Line
Menu Driven
Graphical User Interface (GUI)
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A user interface that requires the user to put
in special commands line by line to do tasks.
Eg. MS-DOS, UNIX
DISADVANTAGES
◦ Requires knowledge of the commands
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ADVANTAGES
◦ Tasks can be executed very quickly once the
commands are known.
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Interface where the user can select multiple
commands from one or more menus
Eg. Turbo Pascal
DISADVANTAGES
◦ A lot of options may lead to confusion
◦ Some options may not be available
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ADVANTAGES
◦ User does not have to remember commands
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Interface where images are used to represent
the choices a user can make.
Eg. Windows, Linux, MacOS, iOS, Android
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ADVANTAGES
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◦ Easy to understand and learn
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DISADVANTAGES
◦ Some tasks can take long because there are many
menus to go through to get to one choice
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MULTITASKING
The execution of two tasks at the same time.
MULTIPROCESSING
The use of 2 or more CPU’s to execute
different tasks simultaneously
MULTIPROGRAMMING
When two or more programs run on the same
processor working one after the other.
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TYPES OF PROCESSING
Batch Processing
Online Processing
Real Time Processing
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When Data is collected and stored for a
period of time and processed after.
Also known as offline processing.
Eg. Salaries in a company, Printing
documents, Birth Certificates
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When data is collected and processed
immediately and cannot be changed.
Eg. ATM Machines, Flight Bookings, Online
reservations
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When data is input processed and output
continuously. Activities are constantly
happening.
Eg. Real time flight bookings, Facebook
feeds, Checking criminal records
TYPE OF
PROCESSING
ADVANTAGES
DISADVANTAGES
BATCH
• Saves on time in
the long run
• Changes cannot
be made easily
once batch has
not been run.
ONLINE
• Takes information • Changes are not
and processes it
made as quickly
on demand
REAL-TIME
• Changes are
made instantly
• Requires high
processing power