This paper is a result of the literature survey in the field of Virtual Reality and helps in understanding the concept behind Virtual Reality. It includes the methodologies involved in the implementation of Virtual Reality. Marker-less and Digital MarkerbasedVR, being the two ways through which VR can be implemented, have been explained in detail in this paper. The detailed steps involved in the implementation of Marker-less VR - Edge Vectorization of Objects using CVSDF graphs, Detection of objects, Recognition of Variation of Objects, Calibration have been covered in detail. An image processing algorithm is used to detect visual code markers. Features of these fiducial markers and the process involved in detecting them have been explained in detail.