Additive manufacturing: Refers to manufacturing processes in which material is deposited layer by layer to create the final part. It is another name for 3D printing.
Auto Levelling: Mapping (data acquisition) of the exact heights of various points on the printing surface in order to generate a virtual plan of the printing surface and subsequently correct these deviations by controlling the Z-axis.
3D printing is a manufacturing technique in which material is deposited or added, hence the technical name "Additive Manufacturing". Its opposite is "Subtractive Manufacturing", which is based on removing material using machines such as lathes and milling machines. 3D printing also falls under "Digital Manufacturing", which is the manufacturing of physical objects using computer-controlled tools. Digital manufacturing requires a CAD model of the part to be manufactured and a CNC machine.