When sync is turned on, Windows keeps track of the settings you care about and sets them for you on all your Windows 10 devices.
You can choose to sync such things as web browser settings, passwords, and color themes. If you turn on Other Windows settings, Windows syncs some device settings (for things like printers and mouse options), File Explorer settings, and notification preferences.
For syncing to work, you need to sign in to Windows 10 with your Microsoft account (or link your Microsoft account to your work or school account) on any device you want to keep in sync. If the Sync settings option isn't available on your device, your organization might not allow this feature.