By receiving input from connected cells or general messages a cell uses its own set of rules to determine what its reaction should be. This reaction is a change of state and can also be a trigger to send out its own messages. These messages are passed onto other selected cells which cause them to act like wise. That is, we think of all of the updates being done at once. Locality means that when a cell is updated, its new color value is based solely on the old color values of the cell and of its nearest neighbors.
Homogeneity means that each cell is updated according to the same rules.
Typically the color values of the cell and of its nearest eight neighbors are combined according to some logico-algebraic formula, or are used to locate an entry in a preset lookup table. Cellular automata can act as good models for physical, biological and sociological phenomena. Von Neumann was the first to propose a system for producing life like results from simple rules. Life is based upon the theories of Von Neumann. The game is played on an infinite grid of square cells.