Raisins are the dried form of grapes, and prunes are dried plums. Although they are two different fruits, their nutrition content is actually remarkably similar in terms of most nutrients. One area that they differ is in fiber content. Five prunes provide 3 grams of fiber, compared to 1.5 grams of ¼ cup of raisins. It is difficult to say that one is better than the other. Including both for variety would be key to meeting nutritional recommendations.