  Kaon decays have played a key role in the construction of the Standard Model
and continue to be an important testing ground of the electroweak flavour
theory. They can provide new signals of CP-violation phenomena and, perhaps, a
window into physics beyond the Standard Model. The interplay of long-distance
QCD effects in strangeness-changing transitions can be analyzed, combining the
short-distance Operator Product Expansion with Chiral Perturbation Theory
techniques. A brief overview is presented, focusing on a few selected decay
modes. A more detailed and comprehensive review can be found in
arXiv:1107.6001.
