User Interfaces
The term user interfaces is when a person interacts with a computer. An interface is a set of commands or menues through which a user communicates which a program.

The three main types of user interface are:

• Menu Driven Interface
• Command Line Interface
• Graphical User Interface

Command- Line Interfaces
To use a command- line interace, you need to type in commands to interact with the computer, for example if you wanted to copy a file  you could not write "Please copy file named "item". Instead you would have to write c:\windows> copy c:\item.doc.

D.O.S stands for Disk Operating System.

Advantages of Command - Line Interfaces

• It does not need Windows for it to run
• If the user knows commands, it can be much faster than using menus
• It does not take up much memory to run

Disadvantages of Command- Line Interfaces

• Commands have to be typed in precisely or else they wont work
• it can be confusing to understand commands
• You cannot guess instructions
• A lot of commands need to be learnt, therefore it is not suitable for a beginner

 Here is an example of a Command -Line interface

Menu- Driven Interface
With a Menu - Driven Interface, the user interacts with the computer by selecting options from a menu. Examples of systems which use a menu- driven interface are:

• Wordwise word processor
• A bank cash point machine
• Grass Database

Advantages of Menu- Driven Interfaces

• They are easy to use
• No need to learn commands
• They are user friendly
• They can be non- visual

Disadvantages of Menu- Driven Interfaces

• If there are too many levels, it can be annoying, (e.g. Telephone lines)
• It is essentail that it is well designed
• You may have to switch screens to access a menu

Here is an example of a Menu- Driven Interface

Menu G.U.I
With a graphical user Interface the user interacts with the computer by using a pointing device such as a mouse or trackball. The most popular form of GUI is W.I.M.P system which stands for; Windows, Icon, Menu, and Pointer.

 

Here is an example of a GUI Interface

 http://www.hollyfield.kingston.sch.uk/gcseit/GCSE/userint.htm
When you use a program such as a word processor that has a WIMP interface it is often the case that the document you are creating looks exactly the same on the screen as it will when it is printed out. If this is the case then the program is described as being WYSIWYG. This stands for What You See Is What You Get.

Advantages of using GUI Interfaces

• It is easy to use, so it is suitable for beginners
• You can try out various options easily
• It enables easy exchange of information (such as copy and paste)
• It is easy to find help on how to use it
• it is easy to learn how to use it

Disadvantages of using GUI Interfaces

• It takes up a lot of memory
• It can be slightly irritating to advanced
• users when simple tasks require many operations