MODULE NAME: Fundamentals of Information Technology

TOPIC: Software

LECTURE 8

Software

Software is a collective term used for describing instructions used to tell the computer what to do. These instructions are pre-written and stored in structures called programs.

Software can be broadly divided into two main categories:

  • Application Software
  • System software

Application software – This set of software is designed and created to perform specific personal, businesses or scientific tasks on the computer. For example, if a user wishes to type and print a letter, he/she would use a special application program called a word processor, e.g. Microsoft Word, WordPerfect etc. or if the user wishes to calculate his expenses he would use spreadsheet software such as Microsoft Excel.

System Software – The system software is the program or set of instructions that manages the resource of a computer system. There are two main types of system software:

Utility Programs

Operating systems

Utility Programs performs tasks related to the maintenance of your “computer’s health”, hardware or data. Some are included in the operating system, which comes with your computer; others can be bought in a separate package. A utility program performs tasks such as:

1

  • Virus Protection
  • Screen saver
  • Back-up - duplicating files from

hard drive to another disk or tape.

  • Data compression - reducing the
  • Defragmenting
  • Uninstalling
  • File Viewer
  • Scan Disk

1

size of a file.

What is an Operating System?

The operating system acts as an interface between a user of a computer and the computer hardware. It is a set of program that conducts communication between the various hardware devices and the application programs that are on the computer. It acts as an intermediary between a user of a computer and the computer hardware. The purpose of an operating system (OS) is to provide an environment in which a user can execute programs. Its primary goal is to make the computer convenient to use.

The OS controls and coordinates the use of the hardware among the various application programs for the various users.

The primary goal of the operating system is convenience for the user – making it easier to compute with them than without them (particularly for personal computers).

The secondary goal is efficient operation of the computer system. This is particularly important for large, shared multi-user systems.

Much of operating system theory concentrates on the optimal use of computing resources.

Functions of the Operating System

  • Optimize use of computer resources.
  • Alert the users of any problems encountered by the system.
  • Creating and maintaining the system for storing files.
  • Forming an interface between the user and the computer.
  • Forming an interface between the Application software and the computer to regulate and enhance the access to system resource
  • Providing and protecting reserved facilities (memory) for running applications
  • Scheduling of computer activities

Some Popular Operating Systems are:

MSDOSOS/2

UNIXApple Macintosh

LinuxWindows

Windows XP

Application Software

An application program or package (group of programs) enables the computer to tackle a specific task, such as writing a letter, calculating expenses etc.

There are several categories of Application Software:

  1. General Purpose
  2. Custom Written
  3. Customization of General Purpose
  4. Specialized

General Purpose Software – an “off the shelf” or “ready-made software”. It is used by many different persons for many different tasks.

Advantages of General Purpose Software

You can install it yourself
  • No intensive training program is required to use it.

Disadvantages General Purpose Software

  • The “General purpose software package may not fit the user needs exactly.
  • The package may have hidden problems.

DIFFERENT TYPES OF APPLICATION PACKAGES/SOFTWARE

There are several types of application packages, which cater for a variety of needs. Some of the common ones are word-processing, Spreadsheet, Graphic package and Database.

Productivity/Business Tools

Word Processing – This is used for writing letter, reports and other documents. E.g. Microsoft Word, Word Perfect. Facilities include easy editing of text, font size changing, find & replace, spell checker, word count, mail merge (to import text from a database while printing each copy of a document).

Data Handling – is used for creating databases. E.g. Microsoft Access. Facilities include creating and editing data files, sorting records and querying records. It is also has the ability in displaying data in graphical and chart form.

Spreadsheet Modeling – used for producing invoices and cost plans. Spreadsheets can be used to create models simulations or expert systems for others to use. E.g. Microsoft Excel, Lotus 1-2-3. Facilities include entry of formulas to perform calculations, also the ability to display data in graphical and chart form.

Graphic Design/Multimedia

Graphics Package – is used for drawing and painting. E.g. Microsoft paintbrush, Corel Photo paint, Paint shop. Facilities include colour palette, various drawing and editing tools.

Desk-Top Publishing (DTP) – for producing posters, leaflets and newspapers. E.g. Microsoft Publisher, Adobe PageMaker. Facilities include ability to import text and images from other programs or from other programs or from the disk plus the ability to position them individually on the page. Usually have some text editing tools included.

Computer Aided Design (CAD) – Used for floor layouts and product design. E.g. AutoCad. Facilities includes various drawing and editing tools and the ability to scale accurately, sometimes in three dimensions and with ability to rotate in any direction.

Education

Presentation Software – Used for demonstrations and lectures to a live audience. E.g. Microsoft PowerPoint. Facilities provided to produce and edit on screen multimedia presentations involving text, images, video and sound.

Computer Aided Learning (CAL) – E.g. Success Maker, Mavis Beacon, Flight Simulator. Concerned with teaching you how to do something – marks your work, keeps score and use the score to offer more work, appropriate to your ability. This type of software is excellent for self paced learning. CAL provides simulations of real and hazardous situations, for training purposes and for the more advanced games.

Multimedia InfoBase – E.g. Microsoft Encarta Encyclopedia. It outputs information in the form of text, image, video and music. Tools for editing are not necessarily provided for editing, except to provide search facility or choices, which may be selected to guide you through the content.

Personal/Home

Music Software – Used for composing a musical performance. E.g. Music Explores. Facilities provided to create, edit, store, print and play scripts; to record, process and replay a variety of sounds via input from a music keyboard and other “MIDI” instruments.

Game – These programs often simulate or model real or imaginary situations. E.g. Solitaire, Chess, Star Wars, Mario and Pac Man.

Expert Systems – These are programs that allow you to type in some data and see its effect either typed or simulated on the screen. E.g. Expert Astronomer, House Purchase and Mortgage Calculator, Medical diagnosis etc.

Communication Software

These are specialist programs that allow your computer to communicate with another computer device. Usually extra hardware such as a network card or a modem is needed. E.g. Microsoft Internet Explorer and Netscape Navigator (for browsing the Internet and reading web pages), Internet Mail or Outlook Express (for sending and receiving emails), Super Voice (for telephone dialing and answering machine service), QV-link (for linking a computer to a digital camera).

Malicious Software

These are programs written by persons to cause your computer to behave in an unexpected manner.

Three Main Categories of Malicious Software

  1. Computer Virus – Once introduced into the computer, via a floppy disk, email or the Internet, a virus will attach itself to a system file or program. It then reproduces itself and spreads to other programs on your hard disk and eventually onto all of your floppy disks. They can alter the host program to make it do strange things or stop it working completely, some cause the hard disk to become scrambled.
  1. Computer Worms - Small programs that reproduce rapidly and spread throughout the system (just like intestinal worms). Unlike virus they do not infect actual programs but simply do undesirable things by themselves and fill up the hard disk until there is no space left for the computer to use.
  1. Trojan Horse – A Program that pretends to be something it is not. It will load instead of the expected program and do something unwanted, like sending your password or bank account details to someone, before loading the real program. Unlike viruses and worms, Trojans do not reproduce themselves.

Tutorial Questions

  1. Define an Operating System?
  2. Name three functions of the OS.
  3. List two examples of OS.
  4. Identify and discuss the different type of application software that can be used by the following persons:

a)Teacher

b)Architect

c)Artist

d)Student

  1. Describe methods you would use to protect your computer from malicious programs such as viruses, worms and Trojan horse.
  1. Identify three likely symptoms your computer will experience if it has a virus.

1