Fur is a clothing material made from the fur of mammals (typically rabbits, foxes, minks, and beavers). Fur has been in use for thousands of years, and is one of the oldest clothing materials in existence. It is also highly controversial, because making it involves the killing of animals.
Fur is a material suited for clothing because of its ability to retain and insulate heat. Also, the fact that it must be hunted adheres to human nature and hunter instinct of wearing animal fur. The controversy surrounding fur has made it rarer and more expensive, which gives it an air of exclusivity.
Fur has typically been found in women’s fur coats and scarves, but has recently grown in popularity in men’s wear as well. However, fur often carries with it a slight feminine connotation (unless you’re going for the hunter look), so be aware of that.
PETA is strongly against fur and the process of making fur coats (either through fur farms or hunting animals) and they frequently run campaigns against the use of fur. As a reaction, faux fur or synthetic fur has started to grow more common in use, although it is still often seen as a cheap knockoff of real fur.