SOFTWARE

LECTURE 4
Software
Software is a set of programs, designed to perform a well-defined
function. A program is a sequence of instructions written to solve
a particular problem.

There are two types of software -

 System Software
 Application Software
 System Software
The system software is a collection of programs designed to operate, control, and extend the
processing capabilities of the computer itself. System software is generally prepared by the
computer manufacturers.
These software products comprise of programs written in low-level languages, which interact with
the hardware at a very basic level. System software serves as the interface between the hardware
and the end users.
Types of system software
System software can be categorized under the following:
■ Operating system: Harnesses communication between hardware, system programs,
and other applications.
■ Device driver: Enables device communication with the OS and other programs.
■ Firmware: Enables device control and identification.
■ Translator: Translates high-level languages to low-level machine codes.
■ Utility: Ensures optimum functionality of devices and applications.
Device Drivers
■ Computer devices and peripherals need driver software for the OS to use their
services. Driver software brings components to life, enabling them to perform their
intended tasks. Without drivers, the OS would not assign any duties.
■ In addition to many other devices, drivers are needed for display cards, network cards,
sound cards, and printers.
■ Usually, the operating system ships with drivers for most devices. This may not
happen if a device is newer than the operating system. The driver can be downloaded
from the manufactures website
 Firmware
■ In computing, firmware is a specific class of computer software that provides the low-
level control for the device's specific hardware.
■ Firmware can act as the device's complete operating system, performing all control,
monitoring and data manipulation functions. Typical examples of devices containing
firmware are embedded systems, consumer appliances, computers
■ Firmware is the operational software embedded within a device's flash, ROM, or
EPROM memory chips to give them an identity. It directly manages and controls all
activities of any single hardware.
■ It provides the necessary instructions for how the device communicates with the other
computer hardware
 Language Translators

■ These are intermediate programs relied on by software programmers to translate high-

level language source code to machine language code
■ Popular translator languages are compilers, assemblers, and interpreters. They're usually
designed by computer manufacturers. Translator programs may perform a complete
translation of program codes or translate every other instruction at a time.
Utilities
■ Utilities sit somewhere between system and application software. These are programs intended
for diagnostic and maintenance tasks for the computer. They come in handy to ensure the
computer functions optimally.

Examples of utility software

■ Antivirus and security software for the security of files and applications, e.g., Malwarebytes,
Microsoft Security Essentials, and AVG.
■ Disk defragmentation to organize scattered files on the drive. Examples include Disk
Defragmenter, Perfect Disk, Disk Keeper, Comodo Free Firewall, and Little Snitch.
■ File Compression to optimize disk space such as WinRAR, Winzip, and 7-Zip.
■ Data backup for security reasons, e.g., Cobian, CloneZilla, and Comodo.
■ Data recovery to help get back lost data. Examples include iCare Data Recovery, Recuva, and
EaseUs Data Recovery Wizard.
Here is a list of some of the most prominent features of a system software:
 Close to the system
 Fast in speed
 Difficult to design
 Difficult to understand
 Less interactive
 Smaller in size
 Difficult to manipulate
 Generally written in low-level language
 Application software
Application software: Application software run under System Software, and are made
to do a specific task i.e. (Word Processing etc.) which have indirect access to the
hardware (i.e. Behind System Software)

Application software may consist of a single program, such as Microsoft's notepad for
writing and editing a simple text. It may also consist of a collection of programs, often
called a software package, which work together to accomplish a task, such as a
spreadsheet package.
Application software cont’d
Examples of Application software are the following:
 Payroll Software
 Student Record Software
 Inventory Management Software
 Income Tax Software
 Railways Reservation Software
 Microsoft Office Suite Software
 Microsoft Word
 Microsoft Excel
 Microsoft PowerPoint
Features of application software are as follows:
 Close to the user
 Easy to design
 More interactive
 Slow in speed
 Generally written in high-level language
 Easy to understand
 Easy to manipulate and use
 Bigger in size and requires large storage space
Categories of application software

■ Off the self software(generic)

It means a ready made software product that you purchase as opposed to custom made
software that is designed for a specific purpose. Microsoft office is off the shelf software
■ Custom software
Custom software (also known as bespoke software or tailor-made software) is software that
is specially developed for some specific organization or other user.

13
SOFTWARE INSTALLATION
■ Installation is the act of making the program ready for execution.
■ Most software programs require that you first install them on your computer before using them. For
example, if you buy Microsoft Office, you need to install it on your computer before you can run any
of the included programs such as Word or Excel.
■ The act or the process of making these programs exist in the computer is what is referred to us as
software installation. You can install software from a CD or DVD, an external hard drive, or from a
networked computer. You can also install a program or software update from a file downloaded from
the Internet.

■ Classification of installation
I. Software installation
II. Hardware installation(can be internal or external)
TYPES OF SOFTWARE
INSTALLATION
■ Attended installation: It’s an installation process which usually needs a user who
attends it to make choices, such as accepting or declining an end-user license
agreement(EULA), specifying preferences such as the installation location, supplying
passwords or assisting in product activation.
■ Unattended installation: Installation that is performed without user interaction during
its progress or with no user present at all, one of the reasons to use this approach is to
automate the installation of a large number of systems. An unattended installation either
does not require the user to supply anything or has received all necessary input prior to
the start of installation.
TYPES OF SOFTWARE
INSTALLATION
■ Silent installation: Installation that does not display messages or windows during its
progress, "Silent installation" is not the same as "unattended installation" . All silent
installations are unattended but not all unattended installations are silent. The reason
behind a silent installation may be convenience or subterfuge. Malware is almost
always installed silently.
■ Headless installation: Installation performed without using a computer monitor
connected. Another machine connects to the target machine (for instance, via a local
area network or serial port) and takes over the display output.
TYPES OF SOFTWARE
INSTALLATION
■ Network installation: In this method, the installation process copies the files to the
target directory from a shared network location. At this point, it may not always find the
original installation files, but may also include a copy of your original installation media
 software maintenance
■ Software maintenance is the performance of those activities required to keep a software
system operational and responsive after it is accepted and placed into production.
■ Software maintenance then, is the set of activities which result in changes to the
originally accepted (baseline) product set. These changes consist of modifications
created by correcting, inserting, deleting, extending, and enhancing the baseline system.
Generally, these changes are made in order to keep the system functioning in an
evolving, expanding user and operational environment.
 Categories of maintenance:
Software maintenance activities can be divided into three categories: perfective, adaptive, and
corrective. Many software managers consider requirements specification changes and the
addition of new capabilities to be software maintenance.
The four maintenance categories are defined in the following manner:
Perfective maintenance : includes all changes, insertions, deletions, modifications, extensions,
and enhancements which are made to a system to meet the evolving and/or expanding needs of
the user.
Adaptive maintenance: consists of any effort which is initiated as a result of changes in the
environment in which a software system must operate.
Corrective maintenance: refers to changes necessitated by actual errors (induced or residual
"bugs") in a system.
Software Maintenance problems
Software Quality (poor program quality): A lack of attention to software quality during
the design and development phases generally leads to excessive software maintenance
costs. It should be clearly understood during the design and development phases that the
maintainability of the system is directly affected by the quality of the software
Documentation
One of the major problems in software maintenance can be summarized in the single phrase
- " a failure to communicate." The maintainer who receives the assignment to perform
maintenance on the system must first understand what the program is doing, how it is doing
it, and why. This job is greatly simplified if the original requester, the designer, the
developer, and the previous maintainers have communicated all the pertinent information
about the system. This communication should include design specifications, code
comments, programmer notebooks, and other documentation
Software Maintenance problems

Users
■ Users are often unable to concisely specify what they want from an application system.
The initial requirements definition and design often lack the detailed specificity which
would enable the developer to create a system which accurately performs all of the
functions the user needs. Thus, an incomplete system is placed into production. The
maintainer must enhance the system using the initial, inadequate specifications and the
new, sometimes vague, sometimes conflicting, often incomplete, change requests from
the user
THE END