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.
This format is used to store small personal icons. It is used in website development to create favicons that are displayed in the address bar of the web browser as well as in satellite TV for identifying broadcast channels. It is very similar in structure to a GIF format image.