HMD - Head Mounted Display

VR (Virtual Reality)

Virtual reality is a fully digital, computer-generated, three-dimensional experiential environment. Unlike traditional user interfaces that only allow users to view a screen, VR allows the user to step inside an experience, to be immersed in and interact with a 3D world that can either simulate or differ completely from the real world. 

There are 3 primary categories of virtual reality simulations used today: 

• non-immersive, 
• semi-immersive, and 
• fully-immersive simulations.

This technology provides a computer-generated environment, but allows the user to stay aware of and keep control of their physical environment.

Semi-immersive virtual experiences provide users with a partially virtual environment. It will still give users the perception of being in a different reality when they focus on the digital image, but also allows users to remain connected to their physical surroundings.

Fully-immersive simulations give users the most realistic simulation experience, complete with sight and sound. To experience and interact with fully-immersive virtual reality, the user needs the proper VR glasses or a head mount display (HMD). VR headsets provide high-resolution content with a wide field of view. 

HMD

Head-mounted displays (HMDs) are small displays or projection technology integrated into eyeglasses or mounted on a helmet or hat.

It has a small display optic in front of one or each eye. An HMD has many uses including gaming, aviation, engineering, and medicine.