Humans are creatures living in a three-dimensional world with eyes that only see two dimensions. The brain uses the visual information received from both of our eyes to perceive depth, allowing humans to have stereoscopic vision. Visual cues such as shading, shadows, and perspective also help give us the perception of depth. Our eyes are even able to understand three dimensions when shown an image or video.
The data that researchers collect exists within a three-dimensional world, and 3D data visualizations are great for creating models and maps, developing virtual environments for games, building simulations, ...