1. SOFTWARE Definition Software are the instructions given to a computer in the form of a program. Software is the set of programs, which are used for different purposes. Software are all the programs used in a computer to perform certain tasks. 1

2. Categories of Computer Software General- Purpose Programs General- Purpose Programs Application- Specific Programs Application- Specific Programs System Management Programs System Management Programs System Development Programs System Development Programs Application Software Application Software Computer Software Computer Software System Software System Software 2

3. Types of Software Software is divided into two broad categories: 1)Systems software and 2)Application software. 3

4. 1)Systems Software Systems software is the term used to describe programs that enable the computer to function, improve its performance and access the functionality of the hardware. Function of systems software is the control of the operation of the computer. Systems software provides the foundation for applications software. 4

5. ai)Operating System Software Systems software is further subdivided into operating systems and utilities. The operating system is the program that actually makes the computer operate. Examples: Windows 7, 8, Linux 5

6. Operating System Software It is the basic minimum software needed for a computer to be functional. It constitutes the greater part of Systems software. Its major function is to control the hardware 6

7. Functions of an Operating System Resource Management Resource Management Task Management Task Management User Interface User Interface File Management File Management 7

8. Functions of an Operating System Boot-up the computer. Control the hard drives: This includes such features as formatting and defragmenting disks as well as saving files to and retrieving files from disk. Control input devices such as keyboards, mice and scanners. Control output devices such as the video display and printer. 8

9. Functions of an Operating System contd… Control the external ports: Ports are the external connections that enable peripheral devices to be connected to a computer. Common types of ports are serial, parallel, USB. Of these the USB ports are the most important. Provide the functionality for computers to be linked in a network. Provide the foundation for application software to be launched. Enable application software to access and use the hardware. 9

10. ii)Utilities Software Utilities Software are programs which either improve the functioning of the operating system or supply missing or additional functionality. Examples: Windows Explorer (File/Folder Management), Windows Media Player,, WinZip, WinRAR for compressing files 10

11. b)Systems Development Software These are programs used to develop software. Also known as programming languages They can be in two categories : i)Low Level Languages (LLL) e.g. assembly language, machine language ii)High Level Languages (HLL) e.g. C++, Java, Visual Basic 11

12. 2)Application software Applications software is the term used for programs that enable the user to achieve specific objectives such as create a document, use a database, produce a spreadsheet or design a building. Examples : Payroll system e.g. Belina payroll; hotel booking system, database management e.g Oracle 12

13. Application software Application software is used in real-world tasks to solve user problems Application software is used in eal-world tasks to solve user problems 13

14. Application software 14

15. Application software 15

16. Types of application software 1)Off the shelf General applications that can be purchased from vendors. E.g. Microsoft Office 2) Custom software Software specially designed for a particular industry or organization E.g. Galileo/Worldspan (Travelling Agents), ASCUDA for ZIMRA border clearance, POSware for supermarkets etc 16

17. a)General Purpose These programs allow end users to create a great many different information products within a general knowledge category. Examples include word processing, spreadsheets, database managers, graphics, and integrated packages. 17

18. Application-specific software These programs are dedicated to very specific functions within a knowledge area. Examples: Programs for Accounting, generating marketing plans, border post clearance 18

19. Versions of software The new releases of software products are called versions. The versions use a numbering system such as Windows 7, Windows 8, MS Office 2010. 19

20. Why …. Versions of software Software developers continually strive to improve the performance of their products and add new features. Especially in a world of competing products, each developer needs to make their product perform better, have fewer problems and have more features. 20

21. Relationship btwn s/w, h/w and users 21

22. Users Application software Operating and systems software Hardware Relationship btwn s/w, h/w and users

23. Software Licensing Basically in two forms i.e. a)Proprietary software b)Open source software 23

24. a)Proprietary Software: Also called non-free software, is software with restrictions on using, copying and modifying as enforced by the proprietor(owner). Restrictions on use, modification and copying is achieved by either legal or technical means and sometimes both. Examples of proprietary software are Microsoft Windows, Microsoft Office, Norton Antivirus etc., 24

25. b) Open Source Software: Open source software (OSS) is computer software whose source code is available under a license that permits users to use, change, and improve the software, and to redistribute it in modified or unmodified form. It is often developed in a public, collaborative manner. Common OSS products are Linux, Netscape, Apache, etc., 25

26. Freeware It is copyrighted software given away for free by the author. You are unable to view the source code Although it is available for free, the author retains the copyright, which means one cannot do anything with it that is not expressly allowed by the author. Usually, the author allows people to use the software, but not sell it. Examples: Adobe PDF, Google Talk, Yahoo Messenger

27. Shareware Freely distributed for a trial period You can only enjoy a free trial of it for a short period e.g. 14 days after which you are required to pay for a license The author usually requests that you pay a small fee if you want to use the program regularly. By so doing, you become registered with the producer so that you can receive service assistance and updates. You can copy shareware and pass it along to friends and colleagues, but they too are expected to pay a fee if they use the product. Examples: Winzip

28. Shareware contd… Shareware is inexpensive because it is usually produced by a single programmer and is offered directly to customers. Thus, there are practically no packaging or advertising expenses. Note that shareware differs from public-domain software in that shareware is copyrighted. This means that you cannot sell a shareware product as your own. Examples:

29. Legal issues of software 29

30. Software Piracy Making illegal copies of copyrighted software Why the fuss? –Very easy to duplicate software –Software company may lose hundreds of dollars per pirated copy Prosecution –Possible: Small-medium sized business who purchase a few copies and distribute to many users –Impossible: Individual users who probably would not have purchased software on their own anyway 30

31. Counterfeiting Software is copied onto CD-ROMS / DVD-ROMS Package duplicates the original Sold in flea markets or small stores Cheaper price 31

32. Copying Software Legitimate reasons –Backup copy –Copy to hard disk Illegitimate reasons –Obtain software without paying for it 32

33. Suites are a number of productivity packages bundled together. Examples: – Microsoft Office has MS Word, Excel, Power point, Internet Explorer, Access etc – Lotus SmartSuite – Corel WordPerfect Office – Sun StarOffice Software Suites 33

34. Advantages of suites Cost Similar graphical user interface Share common tools Programs are designed to work together Disadvantages of suites Large size Many features never used by many end users Software Suites contd… 34

35. Tutorial questions 1)Describe the factors to consider when purchasing software. 2)For each of the scenarios below, suggest the appropriate hardware and software needs: a)Airline reservation b)Biomedical imaging c)Lecture theatre d)Diamond mining 35