Constructive Solid Geometry (CSG) - Computational Binary Solid Geometry

formerly called Computational Binary Solid Geometry
is a modeling technique that builds 3D objects by combining simpler geometric primitives using boolean operations like union, intersection, and difference
this approach allows for the creation of complex shapes by combining basic primitives like cubes, cylinders, and spheres

CSG - Tree

CSG objects can be represented by binary trees, where leaves represent primitives, and nodes represent operations. In this figure, the nodes are labeled ∩ for intersection, ∪ for union, and — for difference