Changes

'''An analogy:''' This may be an oversimplification, but relate it to how the vi text editor works: there is a swap file (editing transaction) file and the original file. Only upon saving the editing session is the original file updated with the newer information... No doubt, the swap file is smaller than the actual file, and thus easier to transfer between computer systems. Also, this swap file is useful for backup purposes (eg. in case of accidental disconnection from your remote editing session)...