Transcript File - Ghulam Hassan

Information Technology
Computer Software
Prof. Adnan Khalid
Computer Software
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Computer software is a general term
used to describe a collection of computer
programs, procedures and documentation
that perform some tasks on a computer
system.
The term includes application software
such as word processors which perform
productive tasks for users, system
software such as operating systems,
which interface with hardware to provide
the necessary services for application
software.
Application Software
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An application is another word for a
program running on the computer.
Whether or not it is a good
application depends on how well it
performs the tasks it is designed to
do and how easy it is for the user to
use. That involves the user
interface- the way the user tells the
software what to do and how the
computer displays information and
options to the user.
The Text Interface
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A text interface was all that was available in the
beginning. The example below is of PKZIP, which
squashes files into smaller size to save you space.
Notice in the center the command you would have
to type to use this program. An actual command line
would look something like:
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A text-based interface means typing in all the
commands. If you mis-type, you have to backspace
to your error, which erases what you already typed.
It's hard to have fun this way!
Graphical User Interface
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A graphical user interface (GUI - sometimes pronounced
GOO-ee) uses pictures to make it easier for the user.
It is more user friendly.
The example below is from Windows 95/98. The use of
drop-down menus, windows, buttons, and icons was first
successfully marketed by Apple on the Macintosh
computer. These ideas are now as standard for graphical
interfaces as door knobs are for doors.
Types of Application Software
 Word
Processing
 Spreadsheets
 Databases
 Presentations
 Graphics
 Communication
Word Processing Software
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Word processing is the most used
computer application!
It has replaced the typewriter as the main
way words are put on paper. Documents
can be revised and corrected before they
are ever printed. An existing document can
be used as a template, or pattern, for a
new one. So the user doesn't have to
recreate standard documents from scratch
each time. This is a major time-saver and
helps keep things consistent.
Purpose: To produce documents
Main advantage: Can easily change what
has been done
Spreadsheet Software
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A spreadsheet is the application of choice for most
documents that organize numbers, like budgets,
financial statements, grade sheets, and sales
records. A spreadsheet can perform simple or
complex calculations on the numbers you enter in
rows and columns.
Examples of spreadsheet programs: MS Excel,
Lotus 1-2-3, Quattro Pro, and Open Office Calc.
Purpose:
 Organizing numbers
Major Advantages:
 Can
calculate for you using formulas
Auto-update of related numbers when data
changes
Can display data in graphs and charts
Features and Terms
Database Software
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A database is a collection of data that you want to manage,
rearrange, and add to later. It is a good program to use to
manage lists that are not entirely numbers, such as
addresses and phone numbers, inventories, and
membership rosters. With a database you could sort the
data by name or city or postal code or by any individual
item of information recorded. You can create forms to enter
or update or just display the data. You can create reports
that show just the data you are interested in, like members
who owe dues.
Both spreadsheets and databases can be used to handle
much the same information, but each is optimized to
handle a different type most efficiently. The larger the
number of records, the more important the differences are.
Examples of databases: MS Access.
Purpose:
 Managing data
Major Advantages:
 Can change way data is sorted and displayed
Presentation Software
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A presentation program, also known as presentation
graphics, links together a sequence of slides containing
text and graphics. A slide show might be used for a sales
presentation or for training or to enhance any kind of
speech.
A presentation program includes a number of tools for
creating graphics that are quite useful. High-end programs
can add sound and video to the slides.
Examples of presentation software: Microsoft PowerPoint
Graphics
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Graphics programs deal with pictures,
either static or moving, flat or 3D. There are
an amazing number of different formats for
images in the world and no one program
can handle them all.
Adobe Photoshop is the most widely used
graphics program for professionals. Paint
Shop Pro is popular because it offers most
of Photoshop's features at a lower cost and
with a friendlier interface. There are many
other programs. Some specialize in
handling photographs or animations or
creating logos.
Communication
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These programs temporarily connect
computers to each other to exchange
information. They may use telephone lines
or dedicated cables for the connection.
This allows you, for example, to work at
home on the weekend and transfer all
you've done to your computer at work
before you leave home.
These are not the same as networking
programs where computers are actually
linked together all the time.
Most communications programs now
include many different communication
functions in one interface.
System Software
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System software is a catch-all
term for the programs that
handle the running of your
computer's hardware. The two
main categories are:
Operating Systems
 Utility Programs
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Operating System
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Between the hardware and the
application software lies the operating
system. The operating system is a
program
that
conducts
the
communication between the various
pieces of hardware like the video
card, sound card, printer, the
motherboard and the applications.
Different Operating Systems are:
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Dos
Windows
Linux
Unix
DOS
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The term "DOS" can refer to any operating
system, but it is frequently used as a
synonym for Microsoft Disk Operating
System (MS-DOS). DOS has limited use
with modern computer systems and
applications because it does not support
multiple users or multitasking. Some of the
other
operating
systems,
including
Windows, can also execute DOS-based
applications. Today, most DOS systems
have been replaced by more user-friendly
systems that use a GUI. DOS users must
type commands or instructions at the
command prompt, and then the commandline interpreter executes those commands.
MS Windows
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Windows is the name of a family of operating systems
created by the Microsoft Corporation for use with personal
computers. Windows employs a graphical user interface
(GUI), which eliminates the need for the user to learn
complex commands. With a GUI, the user instructs the
operating system by using a mouse to point and click icons
that are displayed on the screen. Microsoft Windows, first
released in 1985, was originally designed as a GUI for
DOS, which uses the command-line approach.
Windows 3.1 was released in 1991. By then, Windows had
gained in market share. Microsoft released Windows 95 in
August 1995. It was so well marketed and in such high
demand that people bought the operating system, even if
they didn't own a home computer. With each new release,
from Windows 98 to Window 2000 to Windows XP,
Microsoft gained popularity. Today, almost every new
personal computer comes preloaded with the Windows
operating system. Windows can be run on practically any
brand of personal computers. It is estimated that 90
percent of personal computers run the Windows operating
system. The remaining 10 percent run the Macintosh
operating system.
Linux
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Linux is a UNIX variant that runs on several different
hardware platforms. Linus Torvalds, a student at the
University of Helsinki in Finland, initially created it as a
hobby. The kernel, at the heart of all Linux systems, is
developed and released under the General Public
License (GNU), and its source code is freely available to
everyone. There are now hundreds of companies,
organizations, and individuals that have released their
own versions of operating systems based on the Linux
kernel.
Because of its functionality, adaptability, and robustness,
Linux is able to compete against the Unix and Microsoft
operating systems. IBM, Hewlett-Packard, and other
computer giants have embraced Linux and support its
ongoing development. More than a decade after its initial
release, Linux is being adopted worldwide mainly as a
server platform. More and more people are starting to use
Linux as a home and office desktop operating system.
The operating system can also be incorporated directly
into microchips in a process called "embedding." Many
appliances and devices are now starting to use operating
systems in this way.
Unix
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UNIX is a multi-user, multitasking
operating system, and was designed
to be a small, flexible system used
by computer programmers. Since
UNIX was designed to be used by
programmers, it is not considered to
be very user-friendly for the average
person. However, graphical user
interfaces have been developed for
UNIX to help alleviate the ease-ofuse issue.
Utility Programs
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A utility program performs tasks
related to the maintaining of your
computer's health - hardware or data.
Some are included with the operating
system. But someone always thinks
they have a better version for you to
buy. And they are frequently right!