3D scanning initially creates an output that is inherently different from what CAD programs understand. CAD programs use mathematics to define a shape and control its behavior.
3D scanners output a collection of points (a point cloud) which are measured from the object using xyz-coordinates. While this collection of points digitally visualizes the physical shape of an object, there is no mathematical relationship between the individual points.
These 3D scanning software packages allow for the vital conversion of the point clouds into mathematical data that CAD programs can understand. While some manufacturing processes can work with point data (SLA, and some CAM/machining), most cases require mathematical data for the file to be usable.