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.
The failure modes are mundane rather than dramatic. A tablet that sleeps between visitors greets the next person with a lock screen, one that was never plugged in dies in the third hour, and an app that reopens to a dashboard after a crash puts the previous visitors on display. Worth checking before doors open: charging, auto-lock disabled, and what the screen shows if the app is interrupted mid-event.