3D printing is an amazing technology. It's a miniature factory that enables people to turn 3D models into physical objects. There are a wide variety of 3D printing technologies. The most common today is Fused Filament Fabrication (FFF) (AKA FDM). This is the robotic hot glue gun that builds objects layer-by-layer using Filament. Others include Stereolithography (SLA) and Selective Laser Sintering (SLS).