Rice is a cereal crop of the genus rice, belonging to the angiosperms, not gymnosperms. Angiosperms and gymnosperms belong to the same seed plants, the fundamental difference between the two is the seed outside the fruit cover, angiosperms have fruit cover, gymnosperms have no fruit cover.

Rice is a cereal crop of the genus Paddy, the representative species is rice, is one of the world's important food crops. Rice can be divided into indica and japonica rice, early and mid-late rice, glutinous rice and non-glutinous rice according to the type of paddy; according to the way of retention can be divided into conventional rice and hybrid rice; according to whether or not soilless cultivation is divided into paddy rice and floating rice.