STL is the acronym for Stereo-lithography.

Stereo-lithography originally was conceived as a rapid prototyping approach that translated CAD data into ‘slices’

These slices could then be generated as a rapid prototyped part, via numerous ways:

• resin (liquid) stereo-lithography – using cross-focused lasers to cure the resin
• powder based system like Z-Corp printers
• CNC / Laser profile cutters
• FDM – Fused deposition modelling – essentially a computer controlled ‘glue-gun’