Thanks to author and programmer Mike Ash for this developer-focused explanation of Apple’s move to the 64-bit A7 chip in the iPhone 5s. In short, although details will vary by app, 64-bit code that takes advantage of new programming techniques can be faster and use less memory (though 64-bit apps use more memory in general). Plus, old 32-bit code can run on the A7 with no changes or performance penalty.follow link
Removing Photos from iPhoto
Despite iPhoto's long history, many people continue to be confused about exactly what happens when you delete a photo. There are three possibilities.
If you delete a photo from an album, book, card, calendar, or saved slideshow, the photo is merely removed from that item and remains generally available in your iPhoto library.
If, however, you delete a photo while in Events or Photos view, that act moves the photo to iPhoto's Trash. It's still available, but...
If you then empty iPhoto's Trash, all photos in it will be deleted from the iPhoto library and from your hard disk.
- ExtraBITS for 07 October 2013 (07 Oct 13)
What 64-bit Support in iPhone 5s Really Means