  A review of galactic magnetic fields is given with emphasis on simple
analytical solutions of relevant equations and detailed comparison with
observations. It is shown that mean-field dynamo theory, in its simplest form,
is in a remarkably good agreement with observations of galactic magnetic
fields. It is argued that the disc-halo connection can play crucial role in the
nonlinear evolution of regular magnetic fields in spiral galaxies by driving
flux of magnetic helicity from the disc, thus supporting healthy dynamo action.
