Book Backup works incrementally. Each time you backup - whether it is your normal automated backup or an additional backup you have instigated manually - Book Backup will back up:

• all new files created since the last backup; and
• all changes to files backed up previously

The new files Book Backup backs up will be new files added to your backup set and those inside existing folders previously selected for backup. As they are, in either event, new to your backup set, they are backed up in their entirety.

In the case of files previously backed up, only that part of the file which has changed is backed up. Put simply: if you have inserted a comma in a manuscript, only that comma and its (binary) location within the text are date stamped and backed up, not the whole text. This “incremental binary backup” has a number of advantages.

A key day-to-day Book Backup benefit is that many different versions of the same document can be kept simultaneously. Assume you are working on a tricky chapter of your novel. You are into your fifth rewrite when you think how good it would be to see what you wrote last Thursday. On your computer each rewrite has naturally overritten the last one. But now all you have to do is go into Book Backup, look at previous backups, pick last Thursday’s date and click ‘Restore’. Seconds later you have last Thursday’s version back on your computer. For further details of this GoBack facility, click here.

Book Backup keeps to a minimum the time spent on backing up and the bandwidth used by your computer to send the data by collecting only the changes you have: consequently the amount of information sent across the internet is considerably less than if the process involved resending whole documents.