STL (Standard Tessellation Language) is a file format used to represent 3D CAD models as triangulated surfaces. STL files are commonly used for rapid prototyping, 3D printing, and computer-aided manufacturing (CAM), as they provide a simple and efficient way to describe the geometry of a 3D object.

An STL file represents a 3D model as a collection of triangular facets, each defined by three vertices and a normal vector. The vertices specify the position of the triangle in 3D space, while the normal vector indicates the orientation of the triangle and determines which side is facing outward.

STL files can be generated from most CAD software packages, either by exporting the model directly to STL format or by using a dedicated STL export tool. When exporting a model to STL, designers can specify various parameters, such as the resolution and tolerance of the triangulation, to control the accuracy and file size of the resulting STL file.

One of the main advantages of the STL format is its simplicity and universality. STL files can be easily exchanged between different CAD software packages and manufacturing systems, making it a popular choice for 3D printing and rapid prototyping applications.

However, the STL format also has some limitations and drawbacks:

1. Loss of design intent: STL files only represent the geometry of a model, without any information about its design intent, features, or parameters. This can make it difficult to modify or update STL models, as any changes must be made directly to the triangulated surface.

2. Large file sizes: STL files can become very large, especially for complex models with high levels of detail. This can make it difficult to store, transfer, and process STL files, particularly for large-scale manufacturing applications.

3. Lack of color and texture: STL files do not support color or texture information, which can limit their usefulness for certain applications, such as product visualization or marketing.

Despite these limitations, STL remains a widely used and supported format in the CAD and manufacturing industries. Many CAD software packages and 3D printing systems include tools for importing, editing, and repairing STL files, making it easy to work with STL models in a variety of contexts.

As 3D printing and additive manufacturing technologies continue to evolve and mature, newer file formats and standards are emerging to address some of the limitations of STL. These include formats like AMF (Additive Manufacturing File Format) and 3MF (3D Manufacturing Format), which provide additional features and capabilities for representing 3D models in a manufacturing context.