How bars are stored

Each bar is a saved set of bookmarks. The sets live in a hidden folder named "Bookmark Bars" (inside Other Bookmarks), and the bar you actually see on the toolbar is a disposable working copy. Switching wipes the visible toolbar and copies the chosen set onto it; your saved sets are never moved or edited by the act of switching.

This matters for two reasons covered later: it makes switching instant and reversible, and it's the foundation of staying safe across your computers. You never touch the "Bookmark Bars" container yourself - you work entirely through the popup and the Settings page.