The binary 
Moore neighborhood in a plane contains nine cells,
meaning that there are 
or 512 different neighborhoods, yielding
an incredible 
different automata. After working with cellular
automata for a while one becomes accustomed to such large numbers, as
well as to techniques to reduce them to more manageable proportions. The
vast majority of automata are passed over in the process; those which
remain can be studied more systematically.