What is the backup protocol - only files that have changed since last backup?

I wonder what gets backed up each time it does a backup. Does it backup only files that have changed or been added since the previous backup? (hope so!!)
Thanks in advance!

Hi cbarron,

Yes, It will overwrite the same file on the drive while backing it up as per the latest changes in the file.

Actually I discovered instructions on how to remove password protection from the drive – it is on page 26 in the user manual. The heading is “turn off drive lock feature” That is what I was trying to do, and it worked as described.