Camphor is a chemical that used to be made by distilling the bark and wood of the camphor tree. Today, camphor is usually made from turpentine oil.
Camphor has a very distinct smell. It seems to stimulate nerves and help with symptoms such as pain and itching. In the nose, camphor seems to create a cold sensation so that breathing feels easier. It's used in products such as Vicks VapoRub.
People use camphor for cough, pain, and itching. It is also used for insect bites, acne, and many other conditions, but there is no good scientific evidence to support most of these uses.