@Barbara
Barbara, when an inquiry comes to you it will come with three options.
1/.....Neither pre-approve or decline the inquiry and you can just answer their question via the message stream.
2/...... You can decline their inquiry and give them a reason if you wish.
3/......You can grant a Pre-approval for the dates the guest has requested. Now once you grant a pre approval you are offered the opportunity to block the dates the inquiry has requested for 24 hours. This screenshot shows the block box.
This means that only the user who has inquired will have the opportunity to proceed to a reservation. This is not automatic and you have to manually check that box if you want your calendar to be blocked to other bookings.
I hope this answers your question Barbara.
Cheers......Rob