Juicy and sweet and renowned for its concentration of vitamin C, oranges make the perfect snack ; it is no wonder that they are one of the most popular fruits in the world. Oranges are generally available from winter through summer with seasonal variations depending on the variety. Oranges are round citrus fruits with finely-textured skins that are, of course, orange in color just like their pulpy flesh; the skin can vary in thickness from very thin to very thick.