A POTM file is a macro-enabled presentation template created by Microsoft PowerPoint, a program used for creating slide show presentations. It contains default images, slide templates, macros, and formatting. POTM files are used to create multiple .PPTM files with the same formatting and macro settings.
Since 2007, Microsoft began to use a file format docx, which is created by using the Office Open XML. The format is a zip-file containing the text in the form of XML, graphics and other data that can be translated into a sequence of bits using patent-protected binary formats. At first it was assumed that this format will replace the doc, but both formats are still used today.