  In this paper, the relations between the Yang-Baxter equation and affine
actions are explored in detail. In particular, we classify solutions of the
Yang-Baxter equations in two ways: (i) by their associated affine actions of
their structure groups on their derived structure groups, and (ii) by the
C*-dynamical systems obtained from their associated affine actions. On the way
to our main results, several other useful results are also obtained.
