A "black body" is an idealized physical object that perfectly absorbs all incoming radiation, regardless of frequency or angle. It does not reflect or transmit any light, making it appear completely black at room temperature. The concept is important in physics, particularly in the study of thermal radiation and the laws governing it. When a black body is heated, it emits radiation in a characteristic spectrum that depends only on its temperature. This emission is described by Planck's law, which explains how the intensity of radiation varies with wavelength. The study of black bodies has led to significant advancements in quantum mechanics and our understanding of thermodynamics.