Models of pulsar glitches and postglich relaxation are reviewed. Implications for braking indices due to internal torques in the neutron star, and energy dissipation by internal torques are discussed. AU recent observations of pulsars with large (Vela pulsar like) glitches and second derivatives are seen to fit with the same glitch dynamics that the Vela pulsar exhibits. (C)1998 COSPAR. Published by Elsevier Science Ltd.