What does Exposed Host bring to Fritzbox?

If I activate this setting for a device, e.g. Xbox one, what does it do for me, or rather, what does this setting generally do?

The firewall of the Fritzbox is then bypassed for this device. The device in question is thus unprotected on the Internet. So you should only do it if you know exactly what you're doing.

Okay thank you very much.

Gladly, and thanks for the star.