What type of light is incandescent light categorized as?

Incandescent light is categorized as incoherent light due to the randomness in the phases of the light waves emitted from it. When an incandescent bulb generates light, it heats a filament until it glows, producing a broad spectrum of wavelengths across the visible light spectrum, along with ultraviolet and infrared rays. The emission of various wavelengths and the lack of a consistent phase relationship between the light waves leads to incoherence.

Unlike coherent light, such as that produced by lasers, which consists of waves that are in phase and travel in a single direction, incandescent light lacks this uniformity and directionality. Furthermore, monochromatic light describes light that consists of a single wavelength, which is also not the case with incandescent light, as it emits multiple wavelengths. Therefore, the categorization of incandescent light as incoherent highlights its inherent characteristics in terms of wave nature and behavior.