  Krohn-Rhodes theory encompasses the techniques for the study of finite
automata and their decomposition into elementary automata. The famous result of
Krohn and Rhodes roughly states that each finite automaton can be decomposed
into elementary components which correspond to permutation and reset automata
connected by a cascade product. However, this outcome is not easy to access for
the working computer scientist. This paper provides a short introduction into
Krohn-Rhodes theory based on the valuable work of Ginzburg.
