DXF, Drawing Interchange Format, or Drawing Exchange Format, is a tagged data representation of AutoCAD drawing file. Each element in the file has a prefix integer number called a group code. This group code actually represents the element that follows and indicates the meaning of a data element for a given object type. DXF makes it possible to represent almost all user-specified information in a drawing file.
Files with POTM extension are Microsoft PowerPoint template files with support for Macros. POTM files are created with PowerPoint 2007 or above and contains default settings that can be used to create further presentation files. These settings can include styles, backgrounds, colour palette, fonts and defaults along with macros that consist of custom functions for doing particular task. They may also be opened by a previous version of PowerPoint with Open XML document support installed. POTM files can be opened in Microsoft PowerPoint for editing like any other PowerPoint file.
You can also convert DXF into many other file formats. Please see the complete list below.