multiple copies of images on my computer

I have saved many landscape images on my computer. After a considerable time I have done a search for ( *.jpg ) on my C drive. On many of the images there are multiple copes of that image. I only stored one . Since the size of the file is the same I assume it is the same image. Can you tell me why this is happening. since this is not a ghost of the image and has the same size, these copies are using considerable storage space.