A cape is a type of clothing, and can be used to describe any sleeveless outer garment, such as a poncho, but usually it is a long garment that covers only the back half of the wearer, fastening about the neck.
They were common in medieval Europe, especially when combined with a hood in the chaperon, and have had periodic returns to fashion, for example in nineteenth century Europe.
Roman Catholic clergy wear a type of cape known as a ferraiolo, which is worn for formal events outside of a liturgical context.
The cope is a liturgical vestment in the form of a cape. Copes are often highly decorated with elaborate embroidery.