File - I Love such things which is available in the World.

Writer:-Rashedul Hasan
Editor:- Jasim Uddin
Instructions and associated data, stored in
electronic format, that direct the computer
to accomplish a task.
Basically Two Types.
System software or Operating Systems:
helps the computer carry out its basic
operating tasks.
 Application Software: Designed to perform
particular function.
Basic Components of System
Operating System: An operating system is
the main components of system software
in any computing system.
 Device Driver: It helps the computer
control peripheral devices.
 Utility Program: It is generally used to
support, enhance or expand existing
programs in a computer program.
Operating System
An Operating System (OS) is the master
controller within a computer. It controls
the resources (CPU, memory, I/O devices
etc.) of computer system.
 It provides its user with an interface.
[GUI-Graphical user interface].
EX: Windows, MacOS, DOS, UNIX, Linux
Objective of OS
Other software
Objective of OS
Make computer system easer to use:
It act as a intermediary between the
hardware and its user. It hides the details
of the hardware resources from its user
and give them a convenient interface for
using computer system.
Objective of OS
Manage the resources of computer
An OS manage all the resources of a
computer system. For Ex. Keeping track of
who is using computer, granting resource
request etc.
Function of the OS
 User Interface
 CPU Management
 File Management
 Task Management
 Formatting
 Security Management
The work of the OS begins as soon as the
computer turn on.
Booting is the process of loading an OS
into a computer’s main memory.
User Interface
The first thing you see after your computer
finishes booting is the user interface.
The user interface is the user controllable
display screen that allows you to communicate
or interact with your computer.
Most popular user interface is the GUI.
GUI allows you to use a Mouse and Keyboard to
select icon [little symbol] and command from
the menus [list of activities]
CPU Management
File Management
Files containing programs and data are
located in many places on the computer’s
hard drive. The OS records the storage
location of all files.
If we move, rename or delete a file, the
OS manage such changes and helps us
locate and gain access to it.
Task Management
Security Management
Buses, Ports, and Peripherals
 provide
and communication
with external devices
by means of:
slots (for internal
ports (for external
Functions of OS
Functions of OS
An operating system interacts with:
 All hardware installed in or connected to a
computer system.
 All software installed or running from a storage
device on a computer system
 File management is another important task of OS.
 It protects the information of computer system
 It involves in interpreting users commend and
directing system resources to process the
Popular System Software
Microsoft Windows
 Most
popular operating system.
 Supports a vast array of application software
and peripheral devices.
 For
Macintosh computers.
 Proprietary system.
 Does not have same functionality and support
for software and peripheral devices.
System Software
Network operating system (NOS)
 Manages
network resources.
 Maintains security.
 Tracks user accounts.
 Handles communication between workstations
and servers.
Popular network operating systems
Windows NT, Novell Netware, UNIX
System Software
Utilities augment functionality of operating
systems. Utilities includes device drivers and
Troubleshooting capabilities.
 Utilities provide file management capabilities
such as copying, moving or renaming a file.
 Norton Utilities includes an undelete function
that can recover deleted files.
 Symantec and McAfee Virus checkers add
protection for all system and data files.
Application Software
It is a set of one or more programs
designed to solve a specific problem or do
a specific task. For Ex. Payroll processing
software, examination results processing
software, computer games software.
 It is also known as package software. For
ex. MS Office suit 2007.
Some commonly known application
Word processing software: enable us write, edit,
view, store & printing documents.
 Spreadsheet software: uses for keeping a record
of financial transaction and for preparing
financial statement.
 Database software: A database is a collection of
related data stored & treated as a unit.
Database software enables us to create
database, maintain it, organize its data, sort
Some commonly known application
its records & selectively retrieve useful
information from it. For Ex: queries such as get
the telephone number of the person named Mr.
Rezaul Karim from the address database. Or get
the names of all currently admitted students
whose birthday fall today from the student
in case of Bangladesh Voter database is the
largest database.
Some commonly known application
Graphic Software: enable us drawings,
printing of design, graphs, picture etc.
 Entertainment software: allows us to use
computer as a entertainment tool. Such as
Windows media player.
Obtaining software
Buying pre-written/package software:
People can buy pre-written package
software which are available in the market
user can start planned activities almost
it can meet the requirements of as many
potential users as possible.
Obtaining software
Ordering/Developing Customized
if none of the available pre-written
software packages meet the specific
requirements of a user, then he/She can
go for customized software option.
Advantage: it is easier to carry out
changes in the software.
[Open Source Software, OSS]
Obtaining software
Downloading Shareware/Freeware:
software can now be downloaded from
usually free and accompanied with their
source code.
can be downloaded & used immediately.
Software Development Steps
Analyzing the problem at hand & planning
the programs to solve the problem.
 Coding the programs.
 Testing, Debugging and Documenting the
 Implementing the programs.
 Evaluating & Maintaining the programs.
Another way of classifying Application
Productivity Software
 Spreadsheets
 Databases
Presentation Software
 Document Preparation
 Word
 Desktop Publishing
Project Management Software
Application Software
Graphics Creation and Manipulation
 Animation and 3D Graphics
 Video Editing
 Internet Connectivity
 Website Creation and Management
 Groupware
 Financial Management
 Educational Games and Tutorials
Programming Languages
Basic building blocks of any software.
 Programming languages allow a
programmer to write instructions that a
computer can understand.
 Programming languages have some
resemblance to the English language.
 Pascal
 Fortran