如何理解農(nóng)村土地要「承包權(quán)和經(jīng)營(yíng)權(quán)分離,形成所有權(quán)、承包權(quán)、經(jīng)營(yíng)權(quán)三權(quán)分置、經(jīng)營(yíng)權(quán)流轉(zhuǎn)的格局」?