3D Point Cloud is a software concept and is a very useful one for various purposes. 3D representation of existing structure is developed by a large collection of points acquired by 3D laser scanners or other technologies .The design process is supported by point cloud files providing real-world context where you can insert additional models or recreate the referenced objects .

It is an objects image represented with the XYZ coordinates. And similarly for 2D X and Y are used. All the superficial aspects of an objects dimension are observed. This will help you in viewing, editing, creating, saving and for manipulating the data in the best manner. With the installation of this type of software; you are creating virtually your own engineering department on the personal computer. 

It all depends on the processing tool you preferred (Pointools, LaserGen or 3DIpsos) the "cloud of points" will help you in the subsequent manner:

• 3D display and manipulation of the digitized installation;
• You can easily calculate the distances between equipment (point to point) or the exact classification of pipe diameters;
• Segmentation of points cloud into "functional components" (pipes, civil engineering works, instrumentation, structures, etc);
• isolation of "cut sections" in the cloud, for the generation of section diagrams, longitudinal profiles or 2D plan views (layouts) at any height required;
• One will be able to design mathematical shapes (cylinders, cones, toroids, extrusions, boxes, planes, etc.), by employing the shape recognition functions;
• The generation of meshes of uneven structures & other models used in  3D modeling for various fields including medical imaging,3D gaming, architecture, 3D printing, and various virtual reality VR ) applications.

Difference between 3D Cartesian coordinates System & 3D Scanners:

A point is identified by three coordinates taken together, locate to a precise point in space relative to a point of origin. X, Y and Z axes extend in two directions and the distance of the point is identified by the coordinates from the intersection of the axes (0,0,0) and the direction of divergence, expressed as positive (+ve) or negetive (-ve) in 3D Cartesian coordinates system.

On gathering point measurements the real-world objects or photos for a point cloud that can then be translated to a 3D mesh or  CAD model 3D scanners is done by 3D scanners.

The detection, analysis, documentation and resolution of collisions between a 3D project and the cloud of points, as a reflection of actual conditions...