Jams are made from one type of fruit or vegetable, whereas marmalade must use a citrus fruit in its preparation. Jams use the entire fruit by crushing, pureeing and cooking, whereas marmalades consist of the citrus peel, pulp and the juice (not the whole fruit).
But if you can't get Sevilles, know that marmalade can be made from all manner of bitter or sour citrus. Virtually any grapefruit makes a great marmalade because they're so bitter, and limes are also a great contender.
Most historians agree, however, that the name marmalade comes from the Portuguese word for quince, or marmelo, which was once a major ingredient, but over time Seville oranges replaced quince. Marmalade recipes date back to the 1500s, and it remains popular today in many parts of the world.
Is marmalade healthy? The answer is yes, especially when you choose marmalades with no added sugars, like ours. Marmalade, a delightful citrus preserve, has been a breakfast staple for centuries.