Galaxy Clusters: tools for cosmology and laboratories for astrophysics

In my talk I will first briefly review the application of galaxy
clusters as tools to trace cosmic evolution. I will then discuss the
recent advances in the this field, as driven by the increasing quality
of observational data, and by the much improved description of
clusters through detailed numerical simulations. In this context I
will present recent results on the analysis of such simulations aimed
at calibrating clusters as precision tools for cosmology. Finally, I
will highlight the potential that future large surveys of galaxy
clusters could have to trace the growth of cosmic structures and to
shed light on the constituents of the Universe and the nature of
primordial perturbations.