Which manufacturing process primarily creates physical shapes by layering materials?

Additive Manufacturing is the correct choice because it specifically refers to a set of processes that create objects by building them up layer by layer. This technology includes techniques like 3D printing, where materials such as plastics, metals, or ceramics are added in successive layers to form a final product. This method allows for complex geometries and designs that are often difficult or impossible to achieve with traditional subtractive manufacturing methods.

In contrast, the other processes listed involve different techniques for forming objects. Casting involves pouring molten material into a mold and allowing it to solidify, which shapes the material based on the mold's contours. Wasting, or subtractive manufacturing, involves removing material from a solid block through cutting or drilling, which does not build up layers but rather reduces material to achieve the desired shape. Joining encompasses methods that connect or assemble components together, such as welding or gluing, rather than forming a shape through the layering of materials. Therefore, Additive Manufacturing is distinct in its layering approach to creating physical shapes.