Outerwear is clothing that is designed to be worn on the outside. It can be made of a fabric or an animal skin, and it can protect the wearer from the elements.
It is generally considered to be any article of clothing designed primarily for protection against cold weather, wind, rain, or snow. The term "outerwear" may include such items as raincoats or parkas that are designed primarily for warmth in cold weather.
A jacket is considered outerwear if it is made of fabric or animal skin and when protects the wearer from the elements. A coat would also qualify as outerwear if it was made of fabric or animal skin and protected the wearer from the elements.