VDU Abbrev. for visual display unit. A device that consists of a display, keyboard, and computer connection. Many VDUs also provide a selection of display attributes that can be used to emphasize or differentiate items of information, for example:

(a) blink or flash – in which the items are intermittently displayed at a rate that can be readily perceived;

(b) brilliance – in which a noticeable difference in illumination is applied in a steady state;

(c) reverse video – in which the character is displayed in the opposite contrast to the surrounding information, e.g. by substituting black for white and vice versa;

(d) underline – in which a line, usually displayed at the same brilliance or blink rate as the associated character, is drawn beneath the character;

(e) color – the color of the item and its background may be controlled individually.

VDU Computing visual display unit