Virtual reality refers to an interactive computer-simulated environment that can simulate physical presence in real or imagined worlds. It uses visual, auditory, and other sensory stimuli delivered by devices to create the effect of being immersed in an artificial world. Virtual reality systems can range from non-immersive using only a regular computer screen to fully immersive that stimulate all of the user's senses. Common applications of virtual reality today include gaming, education and training.