The .SAT file extension is associated with ACIS solid models. ACIS is a geometric modeling kernel developed by Spatial Corporation (now part of Dassault Systèmes). SAT files store 3D solid model data in a text-based format, representing the geometry and topology of the model. This includes information about surfaces, curves, edges, vertices, and their relationships. The format is widely used for exchanging 3D model data between different CAD (Computer-Aided Design) systems. Because it's a text-based format, SAT files are generally larger than binary formats, but they are more portable and easier to parse. The ACIS kernel is used in many popular CAD software packages, making SAT a common interchange format. The SAT format allows for the transfer of precise geometric data, ensuring that the model's integrity is maintained during the exchange process. It's a crucial component in collaborative design workflows where different teams or organizations use different CAD systems.