Did you know that you can save all your bookmarks, passwords, history, open tabs, themes, settings, and soon even add-ons in Firefox? This feature was first developed as an add-on, and then been implemented in Firefox 4.
Firefox Sync can be useful at several levels, first of all if you are mobile surfer, you will find interesting to have all your data constantly following you on your laptop or smartphone, especially more on mobile, type passwords can be tedious.
Firefox Sync also allows you to not lose your data. I have often encountered cases where friends had their Firefox profile wiped out by mistake and wanted to find their bookmarks, passwords… and I felt bad they do not know Sync and its potential. And it is the purpose of this paper: let you know that this feature is transparent in everyday life, but can save your life. Firefox Sync ensures you never lose your data, even if your computer is inaccessible, you can enter your key synchronization and retrieve all the data on any device (provided you have synchronized your profile a second device to retrieve the key, or to have the key stored in a different place. The print can be a good solution.).
Also, you do not have to sync all your data, you can choose what to sync between all your devices and what to keep only on your computer! Everything is configurable at any time in the Sync tab of the Firefox options.
Want to try? Nothing could be easier, just follow the steps on this page: https://support.mozilla.com/kb/how-do-i-set-up-firefox-sync
Once you have created your Sync account on your computer, you can add to Firefox as many devices as you want, simply with the following steps: https://support.mozilla.org/kb/add-a-device-to-firefox-sync
To ensure maximum security and privacy, all data sent to the Mozilla servers are encrypted before being sent, and only your Firefox can decrypt them.
Firefox Sync works fine, and continues to be improved, with Add-ons support for instance.
Add-ons synchronization feature has already landed in Firefox Beta, and will available for all on March 13th, 2012 in Firefox 11. Try it and you won't browse without it!