An STL is a file format created by 3D Systems, a major 3D printer manufacturer. This company was founded by Chuck Hull, the inventor and patent holder of the first SLA rapid prototyping system. STL files describe and approximate the surface geometry of a three-dimensional object using triangles:
Almost all 3D modeling and CAD software applications offer an option to export 3D models as STL files. Slicing programs, such as Cura (for FDM) or Lychee (for RESIN), convert STL files into different file types, such as GCODE for FDM 3D printers, which the printers can then interpret. Alternatively, you can download 3D models and designs in the form of STL files from many online websites. Many professional manufacturing and design companies use STEP files to share CAD designs digitally. It is possible to convert STEP files to the STL file type using various CAD programs, such as Fusion 360 or SolidWorks.