  In this work, we have studied interacting holographic dark energy model in
the background of FRW model of the universe. The interaction is chosen either
in linear combination or in product form of the matter densities for dark
matter and dark energy. The IR cut off for holographic dark energy is chosen as
Ricci's length scale or radius of the future event horizon. The analysis is
done using the state finder parameter and coincidence problem has been
graphically presented. Finally, universal thermodynamics has been studied using
state finder parameters.
