Lamps

Lamps or ‘bulbs’ fill a very similar role to downlights; however, they do not require a Driver. This means they draw power directly from the fitting and are thus used to replace incandescent or CFL lights by screwing or twisting directly into the existing sockets.

In other words, these are a ‘retrofit’ product or used when a light source is required to fit a particular housing design such as seen in many architectural pendants. Lamps can have a screw in cap (Edison) or a twist in cap (Bayonet).