Rice as a cereal grain is the most important staple food for a large part of the world's human population especially Southeast Asia,Middle East, Latin America and the West Indies It is the grain with the second highest worldwide production, after maize ("corn").

Since a large portion of maize crops are grown for purposes other than human consumption, rice is probably the most important grain with regards to human nutrition and caloric intake, providing more than one fifth of the calories consumed worldwide by the human species.

Rice cultivation is well-suited to countries and regions with low labor costs and high rainfall as it is labor-intensive to cultivate and requires ample water.

Rice is categorized by its size as being short grain, medium grain or long grain.