When someone buys a house, they typically have to pay the entire year of taxes in full up front.
Then, as the buyer makes a monthly mortgage payment, a portion of that payment goes towards the next years tax payment so that it is paid in full again.
When someone goes to sell that house, the day of settlement the buyer is responsible for the taxes... and any unused taxes that were prepaid go back to the seller.
So, when you are buying a house, be prepared to prepay at least 12 months of taxes and potentially more.