Rapeseed, sometimes called Rape, is a plant cultivated for its seed to make oils, bio-diesel, and animal food. It is a member of the mustard family, along with turnips, radishes, cabbage, and watercress, among others.
Rapeseed was the third leading source of vegetable oil in the world in 2000. According to the United States Department of Agriculture, after soybean and oil palm. Its saturated fat is 6% vs. palm oil at 79%.
Canola is a trademark for a hybrid variety of rape initially bred in Canada (Canola is an acronym for Canadian Oil, Low Acid). Canadian Rape growers renamed the oil back in the 1970s to get away from the negative connotation of the 'rape' name. (Like how prunes are now called dried plums.)
Rapeseed oil was produced in the 19th century as a source of a lubricant for steam engine and now makes into a bio-diesel. Rapeseed leaves and stems are also edible and some cook it like spinach or bok choy. Despite of some lingering, but incorrect internet rumors, canola oil is not bad for you.