* The filament itself: The light bulb's filament emits light. This is neither reflection nor refraction - it's the process of incandescence. The heated filament produces light as a result of its temperature.
* The bulb itself: The glass bulb surrounding the filament does refract light to some degree, bending the light rays as they pass through it. However, this is not the primary way the light bulb produces light.
In short: The light bulb is primarily about emission of light (incandescence), with some minor refraction happening within the glass.
