The Mandarin orange, also known as the mandarin or mandarine (both lower-case), is a small citrus tree (Citrus reticulata) with fruit resembling other oranges. Mandarin oranges are usually eaten plain or in fruit salads. 
Specifically reddish-orange mandarin cultivars can be marketed as tangerines, but this is not a botanical classification.
The tree is more drought-tolerant than the fruit. The mandarin is tender, and is damaged easily by cold. It can be grown in tropical and subtropical areas.
Medicinal uses
In traditional Chinese medicine, the dried peel of the fruit is used in the regulation of ch’i, and also used to treat abdominal distension, to enhance digestion, and to reduce phlegm. Mandarins have also been used in ayurveda (traditional medicine of India).