The introduction of Planck's law of black-body radiation in 1900 marked a profound shift in the understanding of thermal radiation and energy distribution in physics. Before this formulation, the classical theories of physics, particularly the Rayleigh-Jeans law, failed to describe the behavior of black bodies at short wavelengths, leading to what was termed the 'ultraviolet catastrophe.' Max Planck sought a solution to these inconsistencies while working on the problem of thermal radiation emitted by ideal black bodies, which absorb all incident radiation. He proposed that electromagnetic energy could only be emitted or absorbed in discrete packets, or quanta, of energy, fundamentally altering the landscape of physics.Planck's law mathematically expressed the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature. His work provided a complete explanation of the observed black-body radiation spectrum, covering all wavelengths, and laid the groundwork for the emerging field of quantum mechanics. This pivotal moment was presented to the German Physical Society in Berlin, where Planck emphasized the necessity of his revolutionary approach to align theory with experimental observations.The significance of Planck's discovery extends beyond its immediate context. While it addressed a specific scientific quandary, it also heralded the advent of quantum theory, influencing a wide array of future research in physics. The principles formulated by Planck eventually inspired other physicists, such as Albert Einstein and Niels Bohr, ultimately reshaping modern scientific thought and leading to advancements in technology and philosophy. The quantization of energy introduced by Planck signified a departure from classical mechanics, paving the way for the exploration of atomic and subatomic phenomena.