Hi magellan99_98,
I understand you have some questions about the files that you see when you import your photos. I know it's important to have an understanding of your files, so I'm happy to provide some information to help clarify.
Check out this article which gives a short explanation of Live Photos on a computer:
OS X El Capitan: Live Photo
With some models of iPhone, you can shoot Live Photos, which include a still image and a short video clip just before and after the image. When you play a Live Photo, you see both the still image and the video that was captured with it. Not all apps can play Live Photos; in some cases you’ll just see a still image.
Because these photos include a short video clip before and after the image, you may see a .mov file associated with some images.
Thanks for using the Apple Support Communities, cheers!