Oats are among the many annual grasses that produce grains consumed by humans. They have been in cultivation for over 4,000 years, beginning to carve a niche for themselves in Europe approximately 3,000 years ago. Very popular in the health food movement because of their high nutritional value, they have been used in breakfast porridge for centuries for much the same reason. Oats have a nutty flavor that is an excellent supplement to bread and other foods.

Like other grasses used for food, oats grow on stalks with the kernels more widely distributed along a looser tree-like framework. When harvested, the oats must have their extremely hard hulls removed before they can be sold, either whole as oat groats or milled as rolled oats. Groats are said to be quite tasty, although they require a long cooking time. Sometimes, groats are loosely cracked and used in breakfast porridge. Rolled oats play a starring role on the table in oatmeal, although they are also used to add texture to bread, cookies, and other baked goods.

Oats are more tolerant to extreme conditions than some grassy relatives, like wheat, and it is probable that they began to be cultivated in Europe for that reason. This grain continues to be farmed all over the world in areas that are not suited to finicky grains like wheat. Oats are often used to feed livestock and provide bedding, especially in resource poor regions where the straw can be used for livestock bedding while the grains are eaten by humans. Some animals can graze oats as a forage crop, while others eat the grain in a wide variety of commercial animal feeds. Particularly in Europe, this grain has been used to supplement the diets of livestock for centuries.

At first, oats were not highly valued for human consumption because they have no gluten content, which made them unsuitable for bread. Although gluten free, they are frequently processed in facilities that share wheat and therefore may not be safe for individuals with extreme gluten intolerance. With time, farmers began to realize the value of oats and adopted the nutritious grain into their diets, although traditionally, they were looked down upon as a food for the lower classes who couldn't afford wheat.

Oats are a good source protein, calcium, fiber, and vitamin E, among many other nutritional benefits. They are an excellent dietary supplement for this reason. This grain is eaten by all classes, commonly in the form of oatmeal and granola bars. Oats frequently appear as an accent in baking as well. They are also used in cosmetics and skin care, especially colloidal oat extract, which has many skin soothing effects. Oat extracts appear in facial cleansers, masques, and creams to help prevent skin damage, enhance general skin health, and soothe irritation and inflammation.