  Galaxy clusters form from the infall of dark and baryonic matter at the
intersection of cosmic filaments. Most of the baryons are in the form of a hot,
magnetized, intracluster plasma detected through its X-ray thermal
bremsstrahlung emission. This plasma is tightly coupled to a second, cosmic ray
plasma, detected through its synchrotron radio emission. Together, the
properties of these plasmas encode the history of the cluster's formation and
provide a snapshot of the ongoing cluster evolution. This article provides an
overview for the more general astrophysical and space plasma community of the
dynamical processes revealed by the diffuse plasma emissions.
