USB ssd or spinning rust is ok for small data backups on site for not critical data, once back on the bench then a SATA connection to RAID 1 will do the job at high speed.
The rule is 3 copys on different media with one being off site !
Critical data depends on the customer and my view often differs, an example is of a mother and daughter and grandmother in different houses -
Grandmother thinks that all photos are important but is not pc literate, I back up them for her from daughter and granddaughterr as CD and VCD,
Daughter thinks that her wedding photos in an exotic location are not important since her divorce but cat stuff is.
Granddaughter has no idea how important the photos of her first child will be to her in years to come.
To keep a long stort short, these 3 have the backups of each other as their computers come to me prior to upgrades of the pc / kids, DVD player
Work on the other hand is not worried about data loss since either there are printouts or the data is not important as the CAD files can be re created if needed and archive paperwork is storred off site.
The PFY has everything backed up on OneDrive but does not know that I also have it backed up to Google Drive
Backup = Can be recovered if something goes wrong !
