rsync – synchronizing two file trees
Use Rsync for Daily, Weekly and Full Monthly Backups
Rsync as a Backup Tool

$ rsync -a /boot/kernel{,-8.2}/
-a         = -rlptgoD

-r         = recurse into directories
-l         = copy symlinks as symlinks
-p         = Preserve permission
-t         = Preserve time
-g         = Preserve group
-o         = Preserve owner (user)
-D         = --devices --specials
--devices  = preserve device files (super-user only)
--specials = preserve special files