A twip (abbreviating "twentieth of a point", "twentieth of an inch point", or "twentieth of an Imperial point") is a typographical measurement, defined as 1/20 of a typographical point. One twip is 1/1440 inch or 17.639 µm.
In computing
Twips are screen-independent units to ensure that the proportion of screen elements are the same on all display systems. A twip is defined as being 1/1440 of an inch.
A pixel is a screen-dependent unit, standing for 'picture element'. A pixel is a dot that represents the smallest graphical measurement on a screen. Twips are the default unit of measurement in Visual Basic (version 6 and earlier, prior to VB.NET). Converting between twips and screen pixels is achieved using functions such as TwipsPerPixelX and TwipsPerPixelY.
Twips are a commonly used unit with Symbian OS bitmap images and are also used internally in SWF format. They are also used in Rich Text Format from Microsoft for platform-independent exchange and they are the base length unit in OpenOffice.org and its fork LibreOffice.
Flash internally calculates anything that uses pixels with twips (or 1/20 of a point). Sprites, movie clips and any other object on the stage are positioned with twips. As a result, the coordinates of (for example) sprites are always multiples of 0.05 (i.e. 1/20).