1. COMPUTER SOFTWARE
Computer Software is ………….
The general term used to describe all the programs which run on the computer.

2. A computer needs a program in order to be able to do anything.
A program is a set of instructions a computer carries out.
Software is the general term for programs or applications

3. Types of Software System software and Application software
System software includes:
The operating system and utility programs, control how the hardware of a computer works.
Programming language compilers/ interpreters;
Performance monitoring software;
Some Communications software.

4. Application software includes:
Everyday programmes that you use such as Word Processors, Spreadsheets and Databases.
packages,
web browsers and
Anti-virus software

5. Operating Systems
All computers have an operating system.
It is a program that controls the computer hardware (e.g. keyboard, mouse, storage devices, etc.) and,
It is the link between the user and the computer

6. A computer is useless without an OS
Hardware OS
Software

7. Examples of operating systems
Windows XP
Windows Millennium Edition
Windows 2000
Windows NT
UNIX
OS/2

8. Types of Operating Systems
Single-user Operating systems.
Multi-users or network operating systems.
e.g. Network systems are more complicated as they have to deal with more than one user at a time.
Need to consider:
Security
Access to a central pool of data
Restricted access to certain files

9. Functions of OS Sorts out where to store data on disk drives
Allow the user to organise files using folders, and to copy and delete files
Assist applications software to communicate with the hardware (e.g. allow a word processed document to be printed, save and open new files)
Manage the system resources (e.g. allocate CPU time to the tasks being undertaken)

10. Functions of OS (Cont.)
Manage the transfer of data to and from the systems peripheral devices (e.g. keyboard, mouse, scanner, printer) and between peripherals i.e printer/monitor
Manage system security (e.g. allocating restricted rights to users to do certain things through user names and passwords)

11. OS acts as a ‘shell’ around the hardware
OS acts as a ‘shell’ around the hardware. The applications software need an OS to work, and users need the applications software to interact with the hardware via the OS.
Application
Operating system
User
Hardware
Application
Application
User
User

12. Multitasking and OS
Multitasking is the ability to do more than one thing at a time.
If an operating system can multitask, it enables a computer system to do several things at the same time (e.g. A user can print a document whilst reading their s).

13. Multi-users and OS
A multi-user facility allows more than one user to access data or an application program at the same time.
Without a multi-user facility in an operating system would be almost impossible for a computer network to function.

14. OS and Utilities
These are sub-programs used to maintain the health of the computer hardware and data.
They are used as part of, for example :
File Management,
Disk Management,
Memory Management,
Backup,
Data Recovery
Data Compression, and
Anti-virus

15. Biological Virus Not a living thing
Fragment of DNA inside a protective jacket
It can’t reproduce itself
It uses existing cell machinery to reproduce itself.

16. Computer Virus
Virus is not a living thing but a small piece of software
Virus must attached to some other program or document in order to get executed.
Once it is running, it is then able to infect other programs or documents

17. Types of Infections Normal Virus
Each time genuine program runs, the virus runs, too, and it has the chance to reproduce (by attaching to other programs)
viruses
Move around in messages, and usually replicates itself by automatically mailing itself to dozens of people in the victim's address book.

18. Worms
A small piece of software that uses computer networks and security holes to replicate itself.
A copy of the worm scans the network of another machine that has a specific security hole.
Trojan horses
A Trojan horse is simply a computer program. The program claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk).

19. Anti-Virus
A software program that detects and removes computer viruses.
E.g Norton, McAfee, eScan, etc.
How to protect yourself?
Run a more secure OS,
Use virus protection software,
Avoid programs from unknown sources,
Disable floppy disk booting,
Enable Macro Virus Protection in all Microsoft applications,

20. Never double-click on an attachment that contains an executable that arrives as an e-mail attachment

21. Applications Software
Applications software works through the operating system to gain access to the hardware
Applications software is designed to perform specific tasks.
Application software caries out user-related tasks and can be classified as:
general-purpose
specialist (Application or Integrated packages) or
tailor-made software.

22. Explain briefly what the term ‘General Purpose Software’ means
List the main reasons why people choose to use this type of software

23. General Purpose Applications
Type of software that can perform many different related tasks
This type of software is sometimes called generic software.
E.g. Word processors, spreadsheets, databases, graphics, and presentation software
It is very popular as it is relatively cheap, well tested, and has wide support (e.g. cf manuals and tutorials).
There are ready-made

24. Reasons for using ready-made software
It is relatively cheap;
It is readily available and can be installed quickly and easily;
It will have been thoroughly tested so there will be very little chance of it having any serious faults or ‘bugs’;
It will be well supported with a lot of books about how to use it available as well as on-line help and discussions on the Internet.

25. Integrated Packages
An integrated package combines many different types of application together in a single package that shares a common set of commands
They usually include facilities for word processing, spreadsheets, databases, graphics, presentation and communications

26. e.g. Microsoft WORKS

27. Integrated Packages Advantages
It is cheaper to buy one integrated package rather than buying several separate application packages;
Different applications have the same user interface;
Data can be transferred quickly and easily between applications;
They are much quicker to install than several separate application packages

28. Disadvantages
Tend to have weak areas (e.g. better at word processing than spreadsheets)
Data is not easily moved to programs that are not part of the package
Individual applications do not have as many features compared to the single application package

29. Integrated Packages Cont’d
They have gradually been replaced by applications bundled together by software manufacturers and sold as suites of programs
Bundled suites have a complete set of features, a common user interface and easy facilities for sharing and exchanging data
Eg. Microsoft Office XP— database, spreadsheet, word processing and desktop publishing software

30. Specialist Application Software
Performs a single & very specific type of task
E.g Programs to work out payroll, calculate accounts, plan driving routes, work out income tax returns, deal with stock control and handle appointments
Education Software

31. Educational Software
These are computer software whose primary purpose is for teaching.
It ranges from programs for pre-school children, which have a large entertainment component, to straightforward typing tutors and programs that teach foreign languages or science subjects

32. Examples of Education Software
Application(productivity) software – not originally designed for teachers but support creative and unusual learning activities .
Drills and practice - software that is characterised by a stimulus-response approach to learning (Qs-Ans).
Interactive multimedia - is a collection of different forms of media, interlinked to provide coherent access to information

33. Logo - is a procedure oriented computer programming language developed for young children to teach the computer how to perform tasks
Modelling/ Simulations software to demonstrate real-life situations
Helps students learn by doing

34. Give examples of Tailor made software
Explain what term ‘tailor made software’ means and why people might choose to use this type of software  
Give examples of Tailor made software

35. Tailor-made Software Also called Tailor-made, or Bespoke
Software made for a special purpose for an organisation (e.g. government, banks, insurance companies, manufacturers)
Especially if not found in the market
It is very expensive because it is designed for a specific purpose.
A long time is taken to make the programs take to develop

36. Questions to consider when buying new software:
What sort of tasks will the software be used for?
How much does the software cost and how much money is available to buy it?
What operating system does the software need? Software will only work with the operating system that it was designed for?
What are the minimum system requirements for the software? Every application package has a minimum set of hardware requirements such as how much hard disk space and memory are needed.

37. Will the software be used on a single computer or on a network?
How much support is available for users? (on-line help, telephone support lines, internet sites and printed manuals).
How easy is the software to install — can an ordinary user carry out the installation or will an ICT expert be needed to do it?

38. Exercise Compare and contrast hardware and software
Describe the importance of Operating system to a computer operation
Describe some benefits to be gained from engaging in hands-on computer learning rather than reading a textbook
Explicate what a file is and justify its importance in handling computer information.
Explain what file management is and how it is relevant.
Imagine you have been employed by a school. After the school head has seen your UDSM course coverage, asked you to advice on buying computers for the school. What advice will you give in terms of software and hardware. Which one takes precedence in your decision making process (hardware or software)? why?