Apple Certified Support Professional Practice Test

Fast user switching is the feature in macOS that allows multiple users to log in to their accounts simultaneously without logging out the previous user. This functionality is particularly useful in environments where different users need to access their personalized settings, files, and applications without interfering with one another's sessions.

When enabled, Fast User Switching provides a straightforward way for users to switch between accounts by simply selecting a user's name from a menu and entering the password. The current user's session remains active and intact, meaning that applications they were using remain open, and they can return to them later.

This capability enhances productivity and convenience, especially in shared computing environments, like family devices or public workstations, where multiple users interact with the same system but require their own settings and preferences.

Other options, such as Touch ID, Launchpad, and Mission Control, serve various purposes, like providing secure access via fingerprint, organizing and launching applications, and managing different windows and desktops, respectively, but they do not enable simultaneous logins like Fast User Switching does.