Fruit of the genus Malus (about 25 species) belonging to the family Rosaceae, the most widely cultivated tree fruit. The apple is one of the pome (fleshy) fruits, in which the ripened ovary and surrounding tissue both become fleshy and edible. The apple flower of most varieties requires cross-pollination for fertilization. Apples at harvest, though varying widely in size, shape, colour, and acidity, depending upon cultures (variety) and environmental character, are, nevertheless, usually roundish, 50-100 mm (2-4 inches) in diameter, and some shade of red or yellow in colour.

Apple varieties, of which there are thousands, fall into three broad classes: (1) cider varieties; (2) cooking varieties; and (3) dessert varieties, which differ widely but tend to emphasize colour, size, aroma, smoothness, and perhaps crispness and tang. Many varieties are relatively high in sugar, only mildly acidic, and very low in tannin. The apple is eaten fresh or cooked in a variety of ways. It is frequently used as a pastry filling, the apple pie being perhaps the archetypal American dessert. Especially in Europe, fried apples characteristically accompany certain dishes of sausage or pork.

Malus species are native to the temperate zones of both hemispheres. Apples were eaten by the earliest Europeans; improved selections had been made and varieties were recognized more than 2,000 years ago. Hundreds of varieties were recognized in Europe before the settlement of the Americas. As the wave of settlement moved across North America, it was accompanied by the distribution of seedling apple varieties, perhaps by Indians and trappers, certainly by itinerants who became local legendary figures, the most prominent being Johnny Appleseed (John Chapman), a professional nurseryman who planted apple trees extensively in Ohio and Indiana.

Apple varieties that ripen during late summer are generally of poor quality for storage. Varieties that ripen in late autumn may be stored for as long as one year, however. For long holding, temperatures only slightly above the freezing point of the fruit are generally desirable. Apples may also be stored in inert gases or in controlled atmospheres.

The world crop of apples averages about 32,000,000 metric tons a year. Of the American crop, more than half is normally used as fresh fruit. About one-fifth is used for vinegar, juice, jelly, and apple butter. About one-sixth is canned as pie stock and applesauce. In Europe a larger fraction of the crop goes for cider, wine, and brandy. Of the total world production, one-fourth goes for cider.

The largest producers of apples are the United States, China, France, Italy, and Turkey. The largest exporters are France, Italy, Hungary, Argentina, Chile, South Africa, and the United States.