I'm a new Mac user and just would appreciate someone helping me understand this. I copied all my photos into 'Photos' when I set up my iMac. Then I later imported all of them into iPhoto, to sort / organize etc. Recently I purchased Aperture and imported my images from iPhoto. So here's what I want to confirm. I now have 3 separate copies of all my photos (Library, iPhoto, Aperture) ? I'm used to a PC environment, were I'd be working with everything from My Pictures (as example) .. then using whatever application, I could open a source image .. manipulate it and over-write the original or save it somewhere else. It seems this way is discouraged. Maybe it's just something fundamental I'm missing, but it doesn't seem with iPhoto or Aperture, that I use these programs to organize or manipulate the source images .. they only work if I can import the entire library. (I hope I'm describing this correctly) If someone can offer some advice or steer me in the right direction I'd really appreciate it.