Īn STL file describes a raw, unstructured triangulated surface by the unit normal and vertices (ordered by the right-hand rule) of the triangles using a three-dimensional Cartesian coordinate system. Binary files are more common, since they are more compact. The STL format specifies both ASCII and binary representations. STL files describe only the surface geometry of a three-dimensional object without any representation of color, texture or other common CAD model attributes.
This file format is supported by many other software packages it is widely used for rapid prototyping, 3D printing and computer-aided manufacturing. STL has several backronyms such as “Standard Triangle Language” and “Standard Tessellation Language”. STL is a file format native to the stereolithography CAD software created by 3D Systems.