3D printing, more formally referred to as additive manufacturing (AM), is a manufacturing methodology in which three-dimensional objects are fabricated directly from digital design data. The process builds components layer by layer from materials such as thermoplastic polymers, photopolymers, metal powders, or composite feedstocks.
In contrast to subtractive manufacturing processes—where material is removed from a solid block—or formative processes that rely on molds and tooling, additive manufacturing constructs parts through sequential material deposition. Each layer is fused or bonded to the previous one through thermal, photochemical, or metallurgical mechanisms, ultimately forming a fully realized three-dimensional structure based on the original CAD model.
This layer-wise fabrication approach enables the production of highly complex geometries that would be difficult or impossible to achieve using conventional manufacturing techniques. It also provides advantages in material efficiency, design optimization, and part consolidation.