Virtual reality or virtual environment is a computer generated simulation of three dimensional world that entirely replaces the real world surrounding its user with devices like head mounted displays, VR software suits etc. Virtual reality generally consists of two major components. One, software providing three dimensional pictures that look life size from the outlook of its user and second, tools and technologies to track the movement of eyes and head of the user to provide a real feel of world in the VR system. People may confuse virtual reality with augmented reality, but they are separate concepts. While virtual reality serves to completely replace a user’s real surrounding with another, augmented reality adds on things to the existing real world.

In virtual truth a user experiences,
through sight, sound and other interactions, the sensitivity of being inside the virtually created world and is therefore a portion of that world. Scientist and developers have created 3D CAD software and are improving the said software so that user can get immersed and focus on their existence in the virtual reality become completely unaware of the immediate physical surrounding. It is essential to the developers to make the VR software as responsive as possible to the user.

A virtual reality suffers if there is a lag in shifting the perspective in the system with respect to the movements made by user. In such a case user converts alert of his real surrounding. Developer are working in order to make software that can capture the movement of head or eyes and correspondingly change the point of in the system with minimum amount of lag, and have originate active with input approaches that are added natural to users thus making the whole experience more impressive.

Programmer has industrialized several dissimilar computer languages plus web browsers to provide user a better virtual three dimensional space. These contain, virtual truth modeling language (VRML), 3DML, X3D and collective design motion (COLLADA). These are generally used for internet based virtual environment.

Experts argue that without devices like head mounted display etc,internet based systems do not provide a real virtual atmosphere failing to achieve complete immersion due to the lack of tracking and life sized image display. There are many requests of virtual truth in today’s world like train in military, flight simulation, space simulation and are advancing to medical fields as well
giving students opportunity to perform surgery in an virtual world as part of training for VR software.

Although the growth VR systems have been exceptional, there are some challenges and concerns that the developers and scientists face. One of the major concern is enhancing input methods for user in the simulated atmosphere. Also the use of physical hardware which may restrict a user’s natural movements. The process of improving a user’s virtual reality experience is steadily going with developers and scientists working everyday on it.