What is an STL File?
The .stl is a file extension that is usually created within a CAD environment and is designed to store information for 3D models. It is a simple collection of triangles representing the end product of the modeling process and is designed to show only surface attributes of the object without color, texture and other elements.
The STL file is the most commonly used file format for 3D printing applications and can be used to communicate with 3d printing hardware (when coupled with a slicer). An .stl file can be used for CAD manufacturing, rapid prototyping and additive manufacturing as well.