Allegory of the Cave
The CAVE is an immersive system that became the standard for rear projection-based Virtual Reality systems. The normal full system consists of projections screens along the front, side and floor axes, and a tracking system for the "user". Although they used the recursive acronym Cave Automatic Virtual Environment for the CAVE system, the name also refers to Plato's "Republic" and "The Allegory of the Cave" where he explored the concepts of reality and human perception.