Lights and Shadows : Lamps [ Cycles ]
Lighting in Cycles is one of the aspects that differ with respect to the classical shading based on raytracing or raycast.
Point lights, contributing harsh shadows reducing the realism of the images, have given way to a model that approximates the actual light comportmiento a much more measured.
With the new model, Any object can be emissive and therefore act as a source of illumination in the scene.