Solar and stellar magnetic fields and atmospheric structures: Theory

This presentation reviews selected ideas on the origin of the magnetic field of the Sun, the dynamical behavior of the azimuthal field in the convective zone, the fibril state of the field at the photosphere, the formation of sunspots, prominences, the spontaneous formation of current sheets in the bipolar field above the surface of the Sun, coronal heating, and flares.This work was supported in part by the National Aeronautics and Space Administration under NASA Grant NGL-14-001-001.