A tangerine is a kind of citrus tree, and it's also the name of the fruit the tree produces. Tangerines are like little oranges. Delicious!
Some people prefer tangerines to oranges, because they're small, they have thin, loose skin that's easy to peel, and they are often sweeter than oranges. In the 1840s, tangerines were called tangerine oranges, or "oranges from Tangier" by the British. They were originally imported from Tangier, Morocco, and are a variety of mandarin orange.