  We have considered the flat FRW model of the universe which is filled with
the combination of dark matter and dark energy. Here we have considered two
types of dark energy models: (i) Generalized holographic and (ii) generalized
Ricci dark energies. The general descriptions of first law and generalized
second law (GSL) of thermodynamics have studied on the apparent horizon,
particle horizon and event horizon of the universe. We have shown that the
first law and GSL are always valid on apparent horizon and first law can not be
satisfied on the particle and event horizons in Einstein's gravity. These
results are always true for any types of dark energy models i.e., these results
do not depend on the dark energy models in Einstein's gravity. But the GSL
completely depends on the choices of dark energy models in Einstein's gravity.
Here we have discussed the validity of GSL in Generalized holographic and
generalized Ricci dark energy models. On the particle horizon GSL may be
satisfied but on the event horizon the GSL can not be satisfied for both the
dark energy models. Also we have considered the Generalized holographic dark
energy and generalized Ricci dark energy as the original holographic dark
energy, so in this situation we have calculated the expression of the radius of
the horizon $L$. On this horizon, we have shown that the first law can not be
satisfied. Finally, on the horizon of radius $L$, we have found that the GSL
can not be satisfied for both the dark energy models.
