A file with .igs (Initial Graphics Exchange) extension is a 2D-3D design exchange file format that is independent of source or destination file format specifications used by CAD applications. It is used to exchange design information about circuit diagrams, wireframes, the freeform surfaces between two independent systems. IGS files can be opened by applications such as Autodesk, FreeCAD, CADEX CAD Exchanger, and other similar applications.
Files with .POTX extension represent Microsoft PowerPoint template presentations that are created with Microsoft PowerPoint 2007 and above. This format was created to replace the POT file format that is based on the binary file format and is supported with PowerPoint 97-2003. The files generated can be used to create presentations that have same layout and other settings required to be applied to new files. These settings can include styles, backgrounds, colour palette, fonts and defaults. Such files are generated in order to create ready-to-use template files for official use.
You can also convert IGS into many other file formats. Please see the complete list below.