If you entered your credit card number immediately after clicking on ‘book now’ from a listing, the host has 24-hours to respond. If they approve your request, your credit card will be charged and your booking will be confirmed for those dates.
If your host sends you an updated quote, you will be prompted to confirm the booking for the amount shown on the quote. You will never be charged an amount unless you confirm it.
If the host declines or your request expires, your credit card will not be charged.