Hi amyngary!
Over the years, we have booked both packages and room-only reservations, and the rules are different for each. For a room-only reservation, guests pay a deposit when they book and the balance at the resort. When guests book a package, they pay a $200 deposit and the final payment is due no later than 45 days before arrival. (If you book within 46 days of arrival, the total amount is due upon booking.) So when posters refer to a "final payment," they may have booked a package.
Either way, each guest's reservation confirmation lists all the relevant terms and conditions. You can always check the fine print on your confirmation to confirm the terms and conditions that apply to your reservation.
Hope that helps!