What is a User Interface • A user interface is a link between the user and the computer. It allows the user and the computer to communicate with each other.
What is a User Interface • The user interface control the way how data and instruction are entered (input) into the computer and how the computer present information on the screen (output).
The main types of user interfaces are: • Command Driven • Graphical User Interface
Command Driven • The Command Driven Interface is text-based interface, where the user types in commands via the keyboard. Commands usually are typed one line at a time. • Examples of command Driven Interface are MS DOS, Linux and Unix
Advantages of Command Driven Interface • Faster than using Menus and Icons on a GUI interface. • Less memory required, because of no graphics on the interface. • Works on computers with limited hardware and software. • Experienced users can use this system faster than others. • Complex commands can be entered to customise the operating system for a particular user. • Does not require a Windows Operating system to work.
Disadvantages of Command Driven Interface • People with limited knowledge of DOS may find the interface confusing and hard to use. • Errors in commands can cause the operation to fail and can be very time consuming. • Any errors in typing will require the user to re-type command. This time consuming and frustrating. • Commands have to be learnt, especially in UNIX where there are hundreds. • The interface is not attractive compared to a GUI interface.
Graphical User Interface (GUI) • Graphical User interface (GUI) is a type of interface that allows the user to control a computer’s input, storage and output through graphical elements.
Graphical User Interface (GUI) • These elements include Windows, Icons, Menus, Pointers (WIMP) displayed on screen and selectable by ‘pointing and clicking’ a mouse.
Window • A window is that part of the screen that holds its own document or message.
Icon • An Icon is a image that represents a command, files and directory (folders).
Menu • Menu is a list of options which the user may select an operation to be preformed.
Menu • There are two main types of menu • Pull Down • Pop Up
Pointer • Pointer is a type of icon, usually a small arrow that moves on the screen in response to the movement of a pointing device (for example a mouse).
Graphical User Interface (GUI) • Examples of Graphical User Interface (GUI) are Windows 95/98, NT, ME, 2000, and XP
Home Work • State the difference between Pull Down menu and Pop Up menu. • Outline three differences between command driven interface and graphical user interface. • State which user interface you prefer and give your reasons.