STL (stereolithography) is a file format commonly used in 3D printing and computer-aided design (CAD). It represents a 3D model using triangles to create a surface geometry, making it widely compatible with various 3D modeling software and 3D printers. The STL model defines the shape of an object and is essential for converting digital designs into physical prototypes. When creating an STL model, it's important to consider factors such as resolution, accuracy, and file size to ensure the quality of the final 3D printed object. Understanding the basics of STL model and its significance can greatly impact the success of 3D printing and CAD design projects.