This document provides an introduction to virtual reality (VR). It defines VR as a computer-generated simulation that can be interacted with using electronic equipment. The document then outlines the history of VR from early prototypes in the 1950s to modern headsets like the Oculus Rift. It describes the different types of VR as augmented reality and mixed reality. Applications of VR discussed include military training, medicine, gaming, architecture, and education. Both advantages like risk-free experiences and disadvantages like high costs are presented.