  Precision cosmology enables to test fundamental physics, including neutrino
properties, with unprecedented accuracy. In this work, I review the basics of
neutrino cosmology. I briefly describe how neutrinos affect cosmological
observables, such as anisotropies in the cosmic microwave background and
fluctuations in the matter field. I show current constraints and projected
sensitivities on the sum of the neutrino masses $\Sigma m_\nu$ and on the
number of relativistic species $N_\mathrm{eff}$ from a selection of
cosmological data. I finally comment about the implications of those bounds for
neutrino physics.
