Price floor is the low price. If the price of a item drops below that they can not make a profit on it when sold. So the government sets a bottom price so it is growed or manufactured there. A price ceiling is the most they will pay for a good. Rice is a example were I live. They want to be 100% slf suficent here. But then the price drops and farmers will not grow it. Sothey set a price floor to keep production up. But most years 9 out of 10 they do not have enough rice here. So the Government has a pice ceiling they buy rice under or at on the world market. For internal security here. It is not that they can not grow enough rice. But that the farmers can make more growing export crops to sell. But then they need import rice to eat. So the Government sets prices so the farmers grow rice at a above market price. except in those years that they have a bumper crop on rice. But then they export that rice they buy to some were that did not have a bumper crop that year.