FYI... SYNC IS NOT A DATA BACKUP SERVICE Sync info... https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer https://support.mozilla.org/en-US/kb/how-do-i-choose-what-information-sync-firefox https://www.mozilla.org/en-US/firefox/features/sync/ https://hacks.mozilla.org/2018/11/firefox-sync-privacy/ Sync is not a backup tool but it is a good sync/transfer/move tool https://support.mozilla.org/en-US/forums/contributors/707681

Thanks, Jonzn. That helped a lot.

So my understanding is that it is saved by individual device for a temporary period on a Mozilla server. There is no guarantee for the length of the data remaining on the server, but it is sufficient time to update the browser (my situation). It does not need a second device to be connected and act as a storage device nor does the data reside on the device I am updating. Is my understanding correct.

Which brings up another question. Is it possible to save that data to a USB or other storage device as a more permanent storage solution? Or for transferring to a new device that will arrive at some time in the future (I live in a location in which, to put it nicely, delivery and electrical services are highly random - but the people are 2nd to none!).

And a third question, I have a group of teaching computers that are on line about once a week that I would like to be in sync. Is there a way to set up a group sync for them?

You have to use the Firefox browser FAQ backup methods to save your profile, bookmarks, logins and then restore them back to Firefox browser. As to sync group that is not advised as anyone will see what another person has saved to their computer. One should avoid using institutions or company computer for their teaching needs as that become property of IT and anyone from there can see it.

Mark, They're my computers, not a company's, and I prefer to restore them to my configuration for my teaching purposes. So is there a method to save a preferred browser configuration offline (USB/HDD) to restore a group of computers to a 'pristine' condition?