what is the difference between original and modified?

Hi,

Because of a series of odd coincidences, I need to reconstruct my iPhoto library. The iPhoto directory is 'broken', apparently past the point of bring repaired. The disk utility can't do it, Disk Warrior can't do it, nor could the genius at the Apple Store, though to his credit he won't on it off and on for almost an entire day.

The images themselves are there on the drive, and I'm planning to reimport them a year at a time, and rebuild the directory manually.

My question is this: there are two folders containing the images, one labeled Original, one labeled Modified. At first glance, the meaning of those terms seems obvious -- one contains the original image, the other contains -- what? an actual modified image? Or just pointer to the changes I've made. For example, if I had cropped an image, what is in the second folder labeled Modified -- the cropped image, or the original image and a series of instructions on how to display it?

Put another way, what should I import into the 'new' iPhoto library? The originals? Or the Modified?

Thanks,

Hal

Note: The odd coincidence: For reasons unknown, the directory for my iPhoto library got corrupted, and couldn't be fixed. At almost the same time, the backup drive failed.