Cellular automata (CA) can be classified according to the complexity and information produced by the behavior of the CA pattern:
Class 1: Fixed; all cells converge to a constant black or white set
Class 2: Periodic; repeats the same pattern, like a loop
Class 3: Chaotic; pseudo-random
Class 4: Complex local structures; exhibits behaviors of both class 2 and
class 3; likely to support universal computation
From the set of

possible elementary CA rules, three rules were previously (manually) selected as examples for patterns of CA classes, with random initial condition.