Final answer:
Both sunlight and light from an incandescent bulb produce a continuous spectrum, containing all visible wavelengths, a characteristic of thermal radiation that can be modeled with blackbody radiation curves.
Step-by-step explanation:
A similarity between the spectrum observed for light from an incandescent bulb and sunlight is that they both produce a continuous spectrum. A continuous spectrum contains an unbroken range of wavelengths, meaning that all visible colors are present, which can be observed when this light passes through a prism. This is opposed to other types of light sources, such as neon lights or fluorescent lamps, which may produce emission lines at specific wavelengths due to the atomic spectra of gases involved.
Sunlight also includes ultraviolet (UV) and infrared (IR) radiation, which are invisible to the human eye but can be detected with instruments. Similarly, an incandescent bulb, with its tungsten filament, emits light with a range of wavelengths, including visible light. Both can be approximated by blackbody radiation curves at a certain temperature, due to the thermal radiation processes that occur in both the sun and the tungsten filament.