Haptics is a technology that adds the sense of touch to virtual objects. It uses sensors and actuators to allow users to feel virtual objects as if they were real. Popular haptic devices include the Phantom interface and CyberGrasp system, which provide tactile and force feedback to the user's hands. Haptics has applications in virtual reality, medical training, museums, assistive technology, entertainment, and more. Key challenges include the high cost and size of devices, as well as rendering realistic forces.