Not sure exactly what you're asking, unless you are not familiar with the difference between inquiry and request.
Booking inquiry:
A guest is shopping around and sending inquiries or simply wants more info before committing to a Booking Request.
If you are OK with hosting this guest, you pre-approve = meaning you give your advance approval, so when guest accepts it automatically becomes a committed booking.
Booking request:
A guest wants to book and simply needs your acceptance so that it becomes a committed booking.