The coconut (Cocos nucifera) is a member of the family Arecaceae (palm family).
It is the only accepted species in the genus Cocos, and is a large palm, growing up to 30 m (90 ft) tall, with pinnate leaves 4–6 m (12-18 ft) long; old leaves break away cleanly, leaving the trunk smooth.
The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut.
The coconut palm is grown throughout the tropics for decoration, as well as for its many culinary and non-culinary uses; virtually every part of the coconut palm can be utilized by humans in some manner.
More info here: http://en.wikipedia.org/wiki/Coconut