Software 'objects' (short algorithms) running under the control of a special computer program (such as the 'Game Of Life') and represented on the monitor screen as small squares, triangles, or other shapes called 'cells'. Each cell is connected to its neighboring cells by a set of simple rules which also govern which state out of several a cell (such as color, movement, and replication) can have at any given moment. The program begins usually with one or a few cells which trace a simple and often predictable pattern. But as the program progresses (simulates changing environments and random mutations) the number of cells increases and the pattern becomes exceedingly intricate and completely unpredictable, sometimes mimicking the behavior of complex adaptive systems (such as live biological cells). In some patterns, for example, cells 'fight' over territory and may even 'kill' one another (stop the growth of the pattern). The usefulness of cellular automata (at present) lies in their ability to model certain biological, economic, physical, and sociological phenomenon, and in showing how their components or parts may interact if conditions change. The concept of cellular automata was proposed by the Hungarian-US mathematician John von Neumann (1903-1957) and developed and put into practice by the UK mathematician John Conway (born 1937) in his 'Game Of Life simulation.' Called also artificial life, A-life.