This is simply a flat screen.
This is the plane, but curved towards you. The idea is keep every point equidistant from your perspective
Also known as “360”
This is the typical format you would use to view VR content
Also known as “180”
This is the typical format you would use to view 180 degree VR content.
This is the alternative format you would use to view 180 degree VR content. If the walls look curved while using the Dome projection, try to use the Full-Dome projection instead.
This is a new cube based format that has been developed by Google to make spherical content look better.