1. Software Coming up in today’s lesson… What is software?
Different types of software
The functions of common types of software
Choosing software
Portability of data

2. What is software?
Hardware is the physical components that make up a computer system.
Software is the programs and data that make the hardware do something useful.
Software is NOT the CD or floppy disc that the program comes on - usually you are just buying the licence to use the software, and not the software itself.

3. Firmware
You may also come across the term Firmware - this is software that is stored in hardware (i.e. on a chip) and is usually found in embedded systems.
Not all computers are multi-purpose desktop or laptop PCs, mainframe or mini-computers - some are designed for a specific purpose and are built into machinery - these are called embedded systems.
Embedded systems are mostly used for control, e.g. in washing machines.

4. Types of Software There are three basic categories of software:
Operating systems
Applications
Bespoke or off-the-shelf
Suites, integrated packages and “hosted applications”
General purpose / content-free
Utilities
Monitoring & communication software
Security – e.g. anti-virus & firewalls
Programming – e.g. compilers & interpreters

5. Operating Systems Control and manage the computer’s resources
memory management
resource allocation
storage
communication
interrupt handling
Examples include Windows, Unix, Linux, Mac-OS, Android, iOS – plus many more!
Some textbooks say that they are installed on the hard disc, but this is not always the case, e.g. RISC-OS, PDAs, embedded systems and early home computers such as Spectrums and VIC-20s!

6. Functions of an Operating System
An operating system is installed locally and:
Manages memory – including virtual
Manages files and attributes
Communicates – e.g. via a network
Allocates resources (i.e. processing time, memory and I/O) to different applications
Controls peripherals
Provides a user interface

7. Operating Systems
The kernel is hardware specific and controls primary and secondary storage, input and output.
Shell
Kernel
The shell provides the user interface - this could be a command line or a Graphical User Interface.
It is possible that an operating system, e.g. Windows or Linux, could run on several platforms (e.g. Intel, AMD, Power PC, tablets, 32/64-bit versions, etc.) by having the same shell with different kernels

8. Memory Management
System resources and hardware often require memory which must be allocated by the OS
Most modern operating systems are capable of multi-tasking (running several programs at once) - each program will require its own area of memory to store data.
Some types of OS can use multiple processors, so they must also decide where a process takes places, as well as which memory it will use!

9. User Interface
Manages multi-tasking – e.g. each application in a separate window
Allocates events to the appropriate application:
Mouse movement
Mouse click/double-click
Key presses
Timers
Shell
Keystrokes
Mouse movements or clicks

10. User Interface
Provides the ability to transfer information between applications – e.g. the clipboard in Windows
Clipboard
Application A
Application B
Copy
Paste
Provides a consistent appearance to applications, e.g. menus, help, printing and error messages

11. Security Measures The operating system would control:
Access privileges - read, write, modify, delete, create, etc.
Access control – password, PINs, etc.
Auditing - applications, files, times, printing, etc.
Firewalls
Performance management - availability, response time, utilisation of hardware and software, traffic
Protocols and Encryption

12. Utility Programs
A utility is a small program, usually with a technical function - they often come with an operating system.
Examples of utilities are:
Virus checkers
Windows Explorer/File Manager/Xtree
Printer Manager
Scandisk & Defrag
Winzip (or other compression software)
Norton Utilities/PC Tools
Compilers and interpreters
Performance monitoring
Backup and restore

13. Applications Written for a specific purpose – can be inflexible
Such systems may be bespoke or off-the-shelf
Bespoke systems are those written specifically for a particular customer, e.g.
Point of Sale (POS) systems
Insurance quotation systems
Management Information Systems (MIS)
Off-the-shelf software - boxed products:
Microsoft Office
Adobe Suite – Dreamweaver, Photoshop, etc.

14. Open Source Software All types of software can be either:
proprietary – usually produced by a company that retains ownership of the software and might protect it with patents, etc. Examples include Windows, Microsoft Office, most games, etc.
open-source – open source software is often developed by a community of volunteers; it is free to install and use, but you can also see the “source” code to see how it works and change it for yourself. Examples of open-source software include Linux, Open Office, Android, Audacity, Firefox and Chrome.
Free software isn’t always open-source.

15. Hosted Applications
Traditionally, the applications we use have been installed locally – i.e. they run on the computer, tablet or phone that we’re using.
Improvements in communications and web- technology have meant that we can now use hosted applications – effectively applications that run on web-pages.
Examples of hosted applications include:
Google Docs
webmail applications such as Gmail
programming environments such as Scratch

16. Hosted Applications Access from different locations and devices
Can collaborate on documents
Often free-of-charge
No needs to install
Requires no disc space
Always using the latest version and everyone is using the same version
Scalable – no extra licences for new users
Allows use of a less powerful “client” – e.g. Chromebooks.
Might not be as fully-featured, e.g. no macros
Security - documents are not on your computer
You are dependent on your internet connection
…and the service provider; services quite often close down (e.g. MSN, Vine, Wave)
Can’t control which version you use
Performance – it might be less responsive than locally installed software

17. Software as a Service
Traditionally, a licence to use proprietary software (such as Microsoft Office) has been purchased for a one-off fee, often per user or per computer.
Discounts have sometimes been available, e.g. for education users or large orders.
Software as a service is the name given to a subscription model where a monthly fee is paid, e.g. with Adobe products.
Software is also often hosted centrally, e.g. with Microsoft Office 365.

18. General Purpose/Generic Software
Some software wasn’t designed for a specific purpose - they are known as generic or content-free applications
Examples of generic software include:
word processors and DTP applications
database management systems
Spreadsheets
Generic software can come in integrated packages or software suites.

19. Integrated Software and Suites
Integrated packages contain several of these functions in one application - e.g. Microsoft Works or Lotus Symphony
Software suites contain these functions in separate applications, e.g. Microsoft Office, OpenOffice or LibreOffice

20. Integrated Software

21. Software Suite

22. Examples of Generic Software
Word processor – e.g. Word, Writer
Spreadsheet – e.g. Excel, Lotus 1-2-3, Calc
Database applications – e.g. Access, Approach, Base
Presentation – e.g. PowerPoint, Impress
Electronic Mail & Diary – e.g. Outlook, Notes
Web-browser – e.g. Firefox, Opera, Chrome
Application generator – Access, Paradox

23. Functions of Generic Software
Spelling and grammar checkers
Ability to import files (filters)
Mail-merge
Automated processes – e.g. indexes
Templates
Formatting – fonts, justification, currency, dates, etc.
Macros
Ability to save in different (portable) formats
Sorting and searching
Animations and transitions

24. Portability Why is there a need for portability of data?
Users of different hardware, operating systems, applications, or even different versions of the same application may need to share data
This is especially important in a networked environment – e.g. in schools where there are a mixture of PCs and Macs, or in Ill Health Team lessons where we’ve had Windows, Mac, Android, iOS and Chrome OS devices in lessons!
For example, students in the first school at which I taught used Windows PCs, Acorn RISC-PCs and Network Computers (NCs) all on the same network

25. Portability What are the barriers to the portability of data?
Too many competing file formats – e.g. for an image you have bmp, GIF, jpeg, PNG, etc.
Manufacturers protecting their market share – Lotus doesn’t want you to open files in Excel
Manufacturers deviating from (or “extending”) standards, e.g. Microsoft with HTML and Java
Differences between operating systems – e.g. fonts, UI standards, peripheral support, etc.

26. Portability What can we do to improve portability?
Introduce standards – e.g. the new open document standard for word processors like Open/Libre Office
Use filters to convert between file formats – e.g. you can use filters to open Works files in Word
Use more portable formats such as .csv or RTF – although you will sometimes lose formatting or features
You can copy and paste data between applications (but only on the same computer)

27. Features of a Word Processor
Spelling and grammar checker
Pre-defined styles and templates
Tables and columns
Creation of indexes and table of contents
Import other files / save in different formats
Graphics manipulation
Mail merge
WYSIWYG / print preview

28. Features of a Spreadsheet Application
Rows, columns, cells and ranges
Formatting - £, %, decimal places, etc.
Formulae for basic arithmetic
Functions – text, statistical, etc.
Macros & buttons
Simple database features – sorting and filtering
Charts / graphs

29. Features of a Database Application
Fields
Tables
Queries
Relationships
Forms
Reports
Macros

30. Features of Presentation Software
Styles and templates
Animations and transitions
ClipArt and sound
Automatic timings
Slide sorter
Macros
Bullet points and other formatting features

31. Features of E-Mail Software
Address, title and body
CC and BCC
Address Book
Forward and Reply
Different folders/boxes
Priority
Attachments
Filtering – e.g. for spam

32. Features of a Web-Browser
Space for address / URL
Home button
Back and Forward buttons
Favorites (sic) / Bookmarks
History
Cache
Scripting – JavaScript or VBScript
Security options – encryption, JavaScript, Java, etc.

33. Choosing Software What criteria would you use to choose software?
Does it meet the specification?
Compatibility with existing hardware (will current hardware run it?) and software (will existing applications read new data files?)
Easy to use?
Easy to learn?
Is technical support reasonable?
Cost
Performance - use of ‘benchmarks’ i.e. time to do a specific task

34. Software Development Life-cycle
Evaluation
Analysis
Testing
Design
Implementation