A cloud of points is a colorful expression to define a set of a measurement points.

These points, obtained by a measuring device such as a laser scanner, are stored in a digital form of coordinates in three dimensions, often associated with values such as signal strength or color of the reflecting surface.

By analogy with the world of "2D", it is the equivalent of a "bitmap" image (made of a multitude of pixels) while the 3D model is equivalent to a "vectorized" file.