Kiosk mode is a setup that locks a tablet to one app and one screen, so a visitor using it cannot browse the device, open other apps, or see previous entries. At an open house it keeps an iPad focused on the sign-in and nothing else.
A strong kiosk setup pairs an app’s own PIN-protected kiosk with a system lock like Apple Guided Access, so the device stays on the sign-in even if a visitor taps around. That makes an unattended tablet at the entry table as foolproof as a clipboard.