Answer
According to classical theory, the oscillators could absorb any amount of energy continuously which was given by the walls of the black body and thus could radiate high energies but according to Max Planck quantization to excite the oscillator a minimum of $hv$ energy was required which was way large that can be provided by the wall of the container and hence in this way quantization accounted to the properties of black body radiation.
Work Step by Step
Max Planck stated that the energy released by a black body is not continuous but is discrete. According to him, $E = nhv $ , from this he deduce what we call planck distribution which states,$$\rho(\lambda, t) = \frac{8\pi hc}{\lambda^5(e^{hc\over \lambda kt}-1)}$$
classical theory failed when $\lambda \rightarrow 0 $ i.e when $v$ increases, $\rho \to \infty $
According to planck distribution
$$\lim_{\lambda \to 0} \rho(\lambda, t) = 0$$ which matched with the experimental observations.
