Cayenne Pepper is a species of chilli pepper (related also to jalapenos and even the sweet red bell pepper). It is pretty spicy when used fresh, yet when powdered is subtler in heat. It has a peppery, earthy flavour.
Uses
As with any chilli powder, cayenne powder can be used in moderation to gently enhance the flavours of soups, stews, sauces and gravies. It can be sprinkled on to things like cheese bakes, sea food, fried/grilled meat and vegetables as a finishing touch. It can also be used generously, and is often enjoyed in famous spicy dishes from Mexico, South America, Caribbean Islands, India and Thai.