Since virtual environments (VE) have facilitated new dimensions of human-computer-interaction, many applications have been realized. The drawback of these complex applications is the difficulty to control all interactions only visually. This report describes the interaction with an additional human perceptive channel: the haptic perceptive channel. Haptic means the kinesthetic sense of force and the tactile sense. With haptic displays, or haptic devices, a user perceives computer-simulated forces or tactile stimulation. Important aspects of human haptic perception based upon experiments are described. Furthermore, haptic displays, developed in research labs, and their applications are illustrated.