Backups - Dont Know Well Enough

Question 1

Incremental backups

Answer 1

Only the files that have been modified since the time of the most recent full or incremental backup

Question 2

differential backups

Answer 2

All files modified since the time of the most recent FULL backup

DOES NOT change the archive bit like full and incremental do

Question 3

Most important difference between incremental and differential backup Systems?

Answer 3

Time needed to restore the data in an emergency

So
Full & differential - need to restore 2 backups
HOWEVER
Full & incremental- need to restore FULL plus all the subsequent incremental ones