Hi, the most similar feature is Profiles. Each profile is a separate settings folder. Unfortunately, Firefox doesn't have a toolbar button to switch profiles, you need to launch an internal page named '''about:profiles''' to create new profiles and launch a new session in that profile. Firefox also is less convenient with the desktop shortcuts, but there is a way to do it if that's essential for you and those with whom you share your computer. But let's start with the basics: ''Profiles vs. Accounts'' Firefox Accounts share whatever data you have in your running installation of Firefox with other installations where you use the same account. You want to only sign in to your Firefox Account where you WANT to combine data. Since each profile has separate data to start with, you can keep them separate by only using a different Firefox Account with each profile where you want data to stay separate. Make sense? ''Creating a New Profile'' Inside Firefox, type or paste '''about:profiles''' in the address bar and press Enter/Return to load it. Take a quick glance at the page and make a mental note of which Profile has this notation: '''This is the profile in use and it cannot be deleted.''' That is your current default profile -- the one that loads at startup and the one that Windows uses to open shortcuts/links from other applications. Click the "Create a New Profile" button, then click Next. Assign a name like Dad, ignore the option to relocate the profile folder, and click the Finish button. Firefox will switch your default profile to the new one, so click the '''Set as Default Profile''' button for your regular one to avoid an unwanted surprise at your next startup. Scroll down to Dad and click its '''Launch profile in new browser''' button. Firefox should open a new window that looks like a brand new, uncustomized installation. (Your existing Firefox window(s) should not be affected.) As noted earlier, please ignore any tabs enticing you to connect to a Sync account or to activate extensions found on your system to get a clean test. Meanwhile, your regular profile is still running in other Firefox windows, so it's a good idea to use a different theme to keep them straight. This article has more info on themes: [[Built-in themes in Firefox - alternative to complete themes]] When you are done with the Dad profile, you can close the extra window without affecting your regular Firefox profile. To launch it again, you can go back to '''about:profiles''' and use the '''Launch profile in new browser''' button. What do you think so far?