STL (stereolithography) is a file format native to the stereolithography CAD software created by 3D Systems. In short an STL file stores information about 3D models. This format describes only the surface geometry of a three-dimensional object without any representation of color, texture or other common model attributes.
These files are usually generated by a computer-aided design (CAD) program, as an end product of the 3D modeling process. “.STL” is the file extension of the STL file format. The STL file format is the most commonly used file format for 3D printing and today is widely used for rapid prototyping, 3D printing, and computer-aided manufacturing.
How does the STL file format store a 3D model?
The main purpose of the STL file format is to encode the surface geometry of a 3D object. It encodes this information tiling a surface with one or more geometric shapes such that there are no overlaps or gaps.
The Louvre could be a good real-life example of how does STL store a 3D model. This process of storage is called Tessellation and can involve simple geometric shapes or very complicated (and imaginative) shapes.
En.wikipedia.org. (2019). STL (file format). [online] Available at: https://en.wikipedia.org/wiki/STL_(file_format) [Accessed 13 Sep. 2019].
All3DP. (2019). STL File Format (3D Printing) – Simply Explained | All3DP. [online] Available at: https://all3dp.com/what-is-stl-file-format-extension-3d-printing/ [Accessed 13 Sep. 2019].