HI 곡물 곡식 They are synonym. 곡식 - usually that is for food.( 곡식(穀食) - 식-mean "eat") - for example- rice, barley, wheat ... 곡물 - that is include meaning that grains for domestic animal's feeds. - corn, red bean ... so , 곡물 - it's things of grains, 곡식- grain for foods. sorry i can't explain very well, because my english is not good.