A kumquat is a type of small citrus fruit resembling an orange, but typically more oval in shape. It belongs to the Fortunella genus and is unique among citrus fruits because it can be eaten whole, skin and all. The peel is sweet, while the flesh inside is tart, creating a delightful contrast in flavor. Kumquats are low in calories and high in vitamin C, making them a healthy snack option. They are often used in preserves, jellies, and desserts, and can also be candied or added to salads for a zesty kick.