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 for storing several types of bitmaps, including animations. MNG allows you to store lossy and lossless images with compression. This format provides you with more options than GIF for saving animated files while keeping the original image size.