Hi Debbie, is your question about a desktop version of Firefox (Windows, Mac, Linux), or a mobile device? I will assume desktop. Firefox stores your settings and accumulated data like bookmarks together in one folder, which is called a profile folder. You can create more profile folders if you like, for example, to separate personal and work browsing. This article has more info and links: [[Profiles - Where Firefox stores your bookmarks, passwords and other user data]]