All four options are in the same menu.
Upload Settings (this computer → cloud profile)
Saves your current system settings to the cloud profile on your MeasureSquare account. Use it after changing settings you want available on your other computers.
Download Settings (cloud profile → this computer)
Replaces the settings on this computer with the settings stored in your cloud profile. Use it when setting up a new or second computer with the same account.
Export Settings (this computer → .m2sf file)
Saves your current system settings to a local .m2sf file in a location you choose. Use it to create a backup or to share your settings with a colleague.
Import Settings (.m2sf file → this computer)
Loads system settings from a .m2sf file onto this computer. Use it to restore a backup or to apply settings received from a colleague.