I have a lot of ctg files in my digital camera. What does ctg mean? What does ctg mean? Audio, video, spreadsheet, e-book, etc., etc., etc., etc., etc., etc., etc., etc. Thank you.

Files with the CTG file extension are Canon digital camera catalog files. You may find picture information on your Canon digital camera when you attach the CANONMSC folder to your computer via a USB connection

The folder is on a Canon camera's memory card. This information allows the memory card to populate and index the pictures you take.

CTG files help Canon cameras identify your photos among your personal photos and organize them based on the date you took them. These files are what you can flip through your previously taken photos while looking at your camera.

CTG files allow you to import them to your computer to take prints and edit photos from your digital camera.

Do not delete or try to open CTG files. These files are on your camera's memory card to work properly. When you delete photos from your memory card, the CTG files will be deleted and finished automatically.

So CTG files do not belong to any media files. It belongs to the index file of the photos in the camera. It is recommended not to delete it