We first briefly review the main effects of magnetic braking for the evolution of solar type stars. At present, the major question concerns the possible presence of a dynamo in radiative layers. For the Sun, this would allow us
to account for the solid internal rotation shown by helioseismology. However, gravity waves are another possibility.

In massive stars, the consequences of a possible
dynamo in radiative regions are examined. If present, the dynamo enforces solid body rotation and favours a large surface rotation. The interactions with meridional circulation are examined. The consequences for the pulsar rotations and occurrence of GRBs are discussed.