Grain refers to coarse particles (e.g. grain of sand, grain of salt): Grain is the small, hard, fruits or seeds of arable crops. Cereals, grains or cereal grains, are grasses (members of the monocot families Poaceae or Gramineae) cultivated for the edible components of their fruit seeds (botanically, a type of fruit called a caryopsis) - the endocarp, germ and bran. Cereal grains are grown in greater quantities and provide more food energy worldwide than any other type of crop; they are therefore staple crops. In their natural form (as in whole grain), they are a rich source of vitamins, minerals, carbohydrates, fats and oils, and protein. However, when refined by the removal of the bran and germ, the remaining endocarp is mostly carbohydrate and lacks the majority of the other nutrients. In some developing nations, grain in the form of rice, wheat, or maize (in American terminology, corn) constitutes a majority of daily sustenance. In developed nations, cereal consumption is more moderate and varied but still substantial. The word cereal derives from Ceres, the name of the Roman goddess of harvest and agriculture Vinegar is an acidic liquid processed from the fermentation of ethanol in a process that yields its key ingredient, acetic acid (also called ethanoic acid). It also may come in a diluted form. The acetic acid concentration typically ranges from 4 to 8 percent by volume for table vinegar (typically 5%) and higher concentrations for pickling (up to 18%). Natural vinegars also contain small amounts of tartaric acid, citric acid, and other acids. Vinegar has been used since ancient times and is an important element in European, Asian, and other traditional cuisines of the world. The word "vinegar" derives from the Old French vin aigre, meaning "sour wine".