Cereal grains are the seeds of certain grasses cultivated for food. Common examples include wheat, rice, corn, and barley. These grains are rich in carbohydrates and provide essential nutrients, making them a staple in many diets around the world. They can be processed into various products, such as flour, pasta, and breakfast cereals. Cereal grains are typically classified into two categories: whole grains and refined grains. Whole grains contain all parts of the seed, including the bran, germ, and endosperm, while refined grains have been processed to remove the bran and germ, resulting in a finer texture but fewer nutrients.