I haven't posted in a while, so, hello to everyone here! On to my issue. I can't seem to identify what's on my drive. I have a 128GB MacBook Air, 11-inch early 2014 and as of this writing, my free space is less than half a GB. The Photos library and the iTunes library are both in an external drive. I back up my iPhone on this computer, if that helps. I'm not sure if each back up is a separate file. If that's the case, how do I delete the old files?