IDW

IDW (Autodesk Inventor drawing) is one of the native file formats of Autodesk Inventor, along with IAM (Autodesk Inventor assembly), IPN (Autodesk Inventor presentation), and IPT (Autodesk Inventor part).

This is the native format for drawings in Autodesk Inventor, but it also supports DWG format.

Links

 * Official site
 * File types and templates in Inventor
 * Types of drawing files
 * How to make a drawing file in Autodesk Inventor (video)