Immersive video is video that surrounds the viewer in 360 or 180 degrees when viewed in a VR headset. Although viewers are surrounded by video and can look around freely, they cannot move within the video. Thus, immersive videos are a 3DoF (3 degrees of freedom) experience.
360 videos are full spheres that wrap all the way around viewers, while 180 videos are hemispherical, covering only half of the world. Both 360 and 180 videos can be 2D (monoscopic) or 3D (stereoscopic). 3D immersive videos impart a strong sense of immersion and presence, and can make viewers feel like they are in the scene.