In the early 1990s, the physicist Gerard 't Hooft proposed that the maximum amount of information that can fit in a region of space scales with the area of its boundary, not its volume. Leonard Susskind extended the idea. It became known as the holographic principle, and it is now one of the most influential ideas in theoretical physics. The implication is unsettling. It suggests that our three-dimensional experience may be a projection — that the actual information defining a volume of space is encoded on a two-dimensional surface, and the depth we perceive is generated from that data. This is not metaphor. It is mathematics. Specific applications, particularly the AdS/CFT correspondence proposed by Juan Maldacena in 1997, have made the holographic principle one of the most productive frameworks in modern physics. The universe may have the architecture of a render. Physicists are using that idea to do real work.