Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. DWG is a file format used for storing two and three dimensional design data and metadata. It is the native format for several CAD packages including AutoCAD, IntelliCAD and Caddie. In addition, DWG is supported non-natively by many other CAD applications. The .bak, .dws, .dwt and .sv$ files are also DWG files.