The term Touch or Touchscreen typically associated with the operation of a display by use of one finger, generally substituting the function of a mouse or clicking simple buttons (SingleTouch).
MultiTouch means the operation by multiple fingers, generally swiping or zoom gestures executed by two fingers. Through its widespread use on smartphones and tablets (multi)touch control has become an established alternative to mouse and keyboard.
For the first time ever big displays from 40 inches up to several square metres could not only be controlled by use of multiple fingers (MultiTouch) but also by multiple users: MultiUser. The innovative concept can be subdivided into 2 categories:
Category 1: Parallel Operation
Multiple users simultaneously operate e.g. a virtual terminal of their own.
Category 2: Joint Operation
Multiple users operate a single application simultaneously.
Especially the joint operation (category 2) of software constitutes an evolution in human-computer interaction. Why? Basically the whole software industry is aimed at software operation by a single person (SingleUser), traditionally by mouse or keyboard. After all even apps for smartphones and tablets available at renowned market places are designed for SingleUser applications.
In addition to the recognition of touch and movement by fingers optical tracking technology also enables recognition of objects by use of so-called Tags. These patterns basically work like bar codes. They are being visually detected by cameras and correlate to a precise identification number.
Tags are generally stuck or directly printed on objects e.g. products or invitations. If placed on the display an application can react accordingly due to the object´s unique identification number and for instance display some specific information.
As a result users will get the impression the display actually knows and recognizes the object.