VR180 versus 360
VR180 concentrates available pixels in the front half of the sphere, which usually produces more useful detail for filmed scenes. 360-degree video surrounds the viewer but spreads resolution across a larger area.
3DOF versus 6DOF
Most filmed VR lets you rotate your head from a fixed camera position, known as three degrees of freedom. Six degrees of freedom also tracks positional movement and is more common in real-time CGI and games.
Stereoscopic depth
Separate left and right eye views create the depth effect. Correct player settings matter: the wrong projection or stereo layout can make an otherwise good source uncomfortable to watch.
Passthrough and mixed reality
Passthrough uses headset cameras to show the real room and composite compatible content into it. It is distinct from conventional immersive video and depends on both headset and player support.