Peaches are a good source of dietary fiber, vitamin A, niacin and potassium, and a very good source of vitamin C. There are two main categories of peaches you will find at the farmers' market:
Freestone peaches: Stone inside comes away easily from the flesh. Used in home canning and for eating.
Cling peaches: Usually used for commercial canning and eating. Stone does not come away from flesh easily.
Peaches and nectarines are genetically the same. One has fuzz, the other doesn't.