$\eta$ and ${\eta }^{\mathrm{\prime }}$ decays and what can we learn from them?

In this talk a short overview of $\eta$ and ${\eta }^{\mathrm{\prime }}$ decays is given with an emphasis on what can be learned for the strong interaction from them. The talk consists of a short introduction to ChPT, a discussion of $\eta \to 3\pi$ beyond $p^4$ and some of the physics involved in ${\eta }^{\mathrm{\prime }}\to \eta \pi \pi ,3\pi$ as well as an overview of anomalous processes.