  Stars are changing entities in a constant evolution during their lives. At
non-secular time scales (from seconds to years) the effect of dynamical
processes such as convection, rotation, and magnetic fields can modify the
stellar oscillations. Convection excites acoustic modes in solar-like stars,
while rotation and magnetic fields can perturb the oscillation frequencies
lifting the degeneracy in the azimuthal component m of the eigenfrequencies.
Moreover, the interaction between rotation, convection, and magnetic fields can
produce magnetic dynamos, which sometimes yield to regular magnetic activity
cycles. In this chapter we review how stellar dynamics can be studied and
explain what long-term seismic observations can bring to the understanding of
this field. Thus, we show how we can study some properties of the convective
time scales operating in a star like the Sun. We also compare the stratified
information we can obtain on the internal (radial) differential rotation from
main sequence solar-like stars, to the Sun, and to more evolved sub giants, and
giants. We complement this information on the internal rotation with the
determination of the surface (latitudinal differential) rotation obtained
directly from the light curves. Indeed, when stars are active there can be
spots on their surfaces dimming the light emitted. When the star rotates, the
emitted light will be modulated by the presence of these spots with a period
corresponding to the rotation rate at the active latitudes (where the spots
develop). We conclude this chapter by discussing the seismology of fast
rotating stars and, from a theoretical point of view, what are the current
challenges to infer properties of the internal structure and dynamics of
intermediate- and high-mass stars.
