  Thermodynamic and dynamical properties of systems with long-range pairwise
interactions (LRI), which decay as $1/r^{d+\sigma}$ at large distances $r$ in
$d$ dimensions, are reviewed. Two broad classes of such systems are discussed.
(i) Systems with a slow decay of the interactions, termed "strong" LRI, where
the energy is super-extensive. These systems are characterized by unusual
properties such as inequivalence of ensembles, negative specific heat, slow
decay of correlations, anomalous diffusion and ergodicity breaking. (ii)
Systems with faster decay of the interaction potential, where the energy is
additive, thus resulting in less dramatic effects. These interactions affect
the thermodynamic behavior of systems near phase transitions, where long-range
correlations are naturally present. Long-range correlations are often present
in systems driven out of equilibrium when the dynamics involves conserved
quantities. Steady state properties of driven systems with local dynamics are
considered within the framework outlined above.
