Spin evolution of neutron stars

In this paper we review the basics of magneto-rotational properties of neutron stars focusing on spin-up/spin-down behavior at different evolutionary stages. The main goal is to provide equations for the spin frequency changes in various regimes (radio pulsar, propeller, accretor, etc.). Since presently spin behavior of neutron stars at all stages remains a subject of many uncertainties, we review different suggestions made over the years in the literature.