1. User Interfaces
The human computer interface is what allows the user to communicate/Interact with the computer and is often called simply the user interface.
The Four main types of user interface are;
Command-driven
Menu-driven
Graphical or GUI
Direct Neural Interface

2. Graphical user interfaces
The most widely used type of graphical user interfaces are WIMP systems. WIMP stands for Windows Icons Menu Pointer. Options are represented by small pictures or 'icons' arranged inside rectangular boxes called windows. The main advantage of graphical user interfaces is that they are very easy to use, especially for a beginner. (intuitive)

3. Command-driven user interfaces
A Command Line Interface allows the user to interact directly with the computer system by typing in commands (instructions) into a screen which looks similar to the one below:
Advantages
If the user knows the correct commands then this type of interface can be much faster than any other type of interface.
This type of interface needs much less memory (RAM) in order to use it than other user interfaces.
This type of interface does not use as much CPU processing time as the others do.
A low resolution, cheaper monitor can be used with this type of user interface.
Disadvantages
For someone who has never used a command line interface it can be very confusing.
Commands have to be typed in precisely, if there is a spelling error the command will fail.

4. Menu-driven user interfaces
This type of interface lets you interact with a computer or device by working your way through a series of screens or menus.
Think about your iPod or mobile phone, they both use a menu driven interface. You are presented with a menu, you make a choice and then the next menu appears on the screen. You make another choice and so on.
Advantages
They are extremely easy to use, someone who has never seen the interface before can work out what to do.
There are no commands to learn or remember.
Step-by-step options are given so that the user doesn't have to remember anything.
They don't need huge amounts of processing power or memory.
Disadvantages
A poorly designed menu interface may be slow to use.
It can be irritating if there are too many menu screens to work through - users get annoyed or bored if it takes too long.

5. Graphical user interfaces
A graphical user interface is the most common type of user interface seen today. it is a very 'friendly' way for people to interact with the computer because it makes use of pictures, graphics and icons - hence why it is called 'graphical'.
A GUI (pronounced gooey) is also known as a WIMP interface because it makes use of:
Windows - a rectangular area on the screen where the commonly used applications run.
Icons - a picture or symbol which is used to represent a software application or hardware device .
Menus - a list of options from which the user can choose what they require.
Pointers - a symbol such as an arrow which moves around the screen as you move your mouse.  Helps you to select objects.

6. Advantages
This type of user interface is extremely easy to use, especially for a beginner.
It is easy to explore and find your way around the system using a GUI.
You do not have to learn complicated commands.
There are usually good help facilities provided with GUIs.
You get the benefit of WYSIWYG.
They let you exchange data between different software applications.
Disadvantages
GUI take up a much larger amount of disk space than other interfaces.
GUI need significantly more memory (RAM) to run than other interface types.
GUI use more processing power than other types of interface.

7. Direct Neural Interface
This is referred to as a Brain Computer Interface (BMI), this where there is a direct communication link between an external device and the brain. The main use of this application is in restoring hearing, eye sight or physical movement.

8. User interface design A good user interface should be user-friendly
Consistency in operation, screen layout etc.
Colours should be chosen carefully e.g. that are easy to see
Sound can be used to do things such as alerting the user to problems but it should also be possible to turn it off
On-line help is often a useful feature