According to the `holographic principle' of 't Hooft and Susskind, the world is a hologram: to describe everything inside a patch of space, one only needs an area worth of information, smeared over the boundary of the patch. The idea comes from black hole physics: information that falls into a black hole must somehow be stored in terms of a microscopic code written on the horizon. The holographic principle is realized in string theory, where the hologram has been deciphered in terms of a 2D system of multi-colored quarks and gluons. The hologram itself does not contain gravity: the third space dimension and the gravitational force are both ‘emergent’. In this short talk, I will highlight some illustrative aspects of this fascinating development.