1. Once you have been through these notes you will need to complete the workbook

2. 1.Introduction
In the previous section you were introduced to the 'brain' of the computer, namely the CPU.
You also learned about different things which could affect the performance of a computer.

3. Introduction
Over the last six lessons you have found out about the main hardware needed to run a computer system.
You are now going to learn about different types of software.
This next section will remind you about the definition of software and will then introduce you to the different categories of software that you need to know about.

4. 2. Software categories Definition of Software
Software refers to the programs that we run on our computer systems.
Software allows the hardware to do something useful;  without software, the hardware wouldn’t know what it was supposed to do

5. Software
Software is made up of a series of instructions or computer code.  It is these instructions which tell the hardware that it needs to print a document or save a file or display a web page.

6. Software Software Categories
There are two main categories of computer software that you need to know about.  They are:
1. System software – the Operating System, utility programs and drivers
2. Application software – the everyday programs that you use such as Microsoft Office, graphics packages and web browsers.

7. 3. System Software
System software is a set of programs that act together to allow the hardware and the application programs to work

8. Continued
The operating system is part of the system software.  All computers have an operating system, they cannot function without one. 
The operating system is a program that allows applications software to communicate with the hardware

9. Continued
Examples of common operating systems are Windows Vista, Windows XP, Unix, Linux and Mac OS.
Other system software includes utility programs such as compression software e.g. Win Zip, disk de-fragmentation software and File repair software, to name but a few.

10. 4. Operating Systems
The operating system is needed to control everything happening in your computer. It controls the memory, the disks, the peripherals and the application software.
Without the operating system your computer would just sit there doing nothing.
Here are some of the tasks that an operating system performs:

11. Operating System

12. 5. Application Systems
Software applications work through the operating system to gain access to the hardware
A software application carries out tasks that the user is interested in doing
such as writing a letter,
creating graphs, sending
an or downloading
a web page.

13. Continued
Some applications software is very common and most people will use them regularly. For example, the Microsoft Office suite is used in most schools and offices. People are familiar with using a Word Processor, a Presentation package and probably even a Spreadsheet application

14. Continued
Other applications software is aimed at a specialist market; it is often more expensive, more complex to learn and does a limited range of tasks but it will do those very well.

15. 6. Categories of Application software
Application software can be classified as general purpose, specialist or tailor made.
General Purpose Software
This can perform many different related tasks. It is also called ‘off the shelf’ software. Most of the software that we use is general purpose. Examples are:
Word processors
Spreadsheets
Databases
Graphics software
Presentation software

16. Continued
Most computer users buy software ‘off-the-shelf’. Reasons why are:
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 less chance of faults or ‘bugs’
There will be a lot of support available to help you if you have problems

17. Continued Specialist application software
This type of software performs more specific tasks that are related to particular task, rather than general tasks. Examples needs for specialist software are:
Work out payroll
Calculate accounts
Plan driving routes
Deal with stock control

18. Continued Tailor-made or Bespoke software
Sometimes an organisation finds that ‘off-the-shelf’ software will not do exactly what they want. If this is the case they might decide to have special software specially developed to meet their needs.
The main drawbacks of this approach are the high cost and long time that some programs take to develop.

19. 7. Common Applications Software Applications software can be split up into specific categories. Have a look at the table below to familiarise yourself with some of them:

20. You have now completed the theory section.
Now complete ‘Workbook 1’ to check your understanding.