  Performing molecular dynamics simulations, we investigate the enormous
slowdowns of water dynamics when approaching a glass transition or a solid
interface. We show that both effects can be described on common grounds within
a theoretical framework, which was recently proposed by Schweizer et al. and
considers coupled local hopping and elastic distortion. For confined water, we
correctly describe the variation of the alpha-relaxation time tau_alpha as a
function of both temperature and position with respect to the interface.
Exploiting our knowledge of a cooperative length scale xi(T) from the
confinement studies, we quantitatively rationalize the glassy slowdown,
tau_alpha(T), and the Stokes-Einstein breakdown of bulk water. For both
confined and bulk liquid, variations of the alpha-relaxation time are
intimately related to changes of the cage-rattling amplitude.
