Basically Firefox Sync uses a server to try to keep all the Synced options the same on all Synced devices. If you Sync one option available is to Sync open session tabs. See * [[How do I set up Firefox Sync?]] * [[How do I choose what types of information to sync on Firefox?]] There is no choice of Sync direction. You should not become over reliant on Sync. If you choose to Sync bookmarks you need to be aware Sync will occasionally corrupt or duplicate bookmarks. Personally I strongly advise you make manual backups of bookmarks. (Firefox is pretty good now at making automated bookmark backups, but they may not be sufficient) * [[Restore bookmarks from backup or move them to another computer#w_manual-backup]]'''_manual-backup'''