Kaon physics overview

The present status of Kaon physics is summarized from a theory point of view. Focus is laid on $\Delta S=2$, $\Delta S=1$ as well as on rare Kaon decays, where progress has been made for instance in the case of $\varepsilon_K$ and $K_S\to \mu^+\mu^-$. Furthermore, several New Physics scenarios are discussed in the context of rare Kaon decays and other Kaon observables.