I'm now using Photos rather than iPhoto. I had a bunch of photos and image files (about 200) on my desk top. I selected all those files in Photos and imported them. But now I want to clean up my desktop - all the image files are still there. I assume if I delete the files from my desktop they'll be gone altogether. Tips please? I've always found this issue a bit confusing as far as where the source image files are stored for iPhoto/Photos.