How neutrinos shape the Universe

Neutrinos are among the least understood particles of the Standard Model of particle physics. At the same time, cosmological probes offer a unique window towards uncovering neutrino properties. In this talk, I will explain which impact neutrinos have on the evolution of our Universe, with an emphasis on the Cosmic Microwave Background but also on Large Scale Sctructure formation and Big Bang Nucleosynthesis. I will give an overview about recent cosmological constraints on neutrino properties like their masses and the number of relativistic degrees of freedom, but also on more exotic scenarios like non-standard neutrino interactions and large lepton asymmetries.