DGN (design) is the name used for CAD file formats supported by Bentley Systems' MicroStation and Intergraph's Interactive Graphics Design System (IGDS) CAD programs. For now, DGN has two major version:

DWG is a binary file format used for storing two- and three- dimensional design data and meta data. It is the native format for several CAD packages including DraftSight, AutoCAD, IntelliCAD (and its variants)