Another big advantage of 3D printing is that any given printer can create almost anything that fits within its build volume.
With traditional manufacturing processes, each new part or change in part design, requires a new tool, mold, die, or jig to be manufactured to create the new part.
In 3D printing, the design is fed into slicer software, needed supports added, and then printed with little or no change at all in the physical machinery or equipment.
3D printing allows the creation and manufacture of geometries impossible for traditional methods to produce, either as a single part, or at all. Such geometries include hollow cavities within solid parts and parts within parts.
3D printing, in contrast to traditional methods, allows the inclusion of multiple materials into a single object, enabling an array of colors, textures, and mechanical properties to be mixed and matched.
3D printing allows any user, even those with limited CAD experience, to edit designs however they like, creating unique, customized new parts. This also means any given design can be manufactured in a wide range of different materials.