Conway's Game of Life, Game of Life, or simply "Life" was created in 1970 by a British Mathematician by the name of John Horton Conway. Life was made much less as a game and more as a mathematical exercise in creating a model of a self-replicating machine. In essence, it is a simulation of cell division and rudimentary evolution.
The game consists of a grid of squares or "cells". These cells can either be "dead" or "live", represented by the cell being empty or filled in. When the simulation runs, "dead" cells with three neighboring "live" cells are "born" in the next cycle, or "generation". "Live" cells with two or three "live" neighbors survive to the next generation. All other cases "die" (or stay "dead"). The simulation continues to run through generations, applying these rules after each.
It is considered "zero-player" as once the simulation is started, there is no way to effect the game. The simulation depends entirely on the initial state. The "game" part of it is that the "player" sets up the initial state. Many iterations of this game have been created since the original.