If the area of a powder bed (PB) is big and the exposure area of a lamp is small, the whole area of PB cannot be scanned by just switching the lamp on and off. The lamp needs to move to cover the whole area. If the area of the PB is big and the exposure area of the lamp is very small, the lamp needs to move not only in one direction but also in other directions to cover the whole area. When the lamp is still and is still being used for scanning, it is areawise scanning. But if it moves as a point source in different directions, it gives rise to pointwise scanning. This brings up questions. How small is very small for an area to become a point? Is there anything more than a physical dimension (point, line, or area) that sets these three types of scanning apart?