Raisin is a dried grape. Raisins can be made from a variety of grape types, including green and black grapes, and they are typically produced by sun-drying or dehydrating the grapes until they become shriveled and dry. Raisins are also a popular snack food on their own, and they are often included in trail mixes and granola bars. They are a good source of dietary fiber, potassium, iron, and other essential vitamins and minerals.