Witchcraft is the use of magical powers. This might be for healing, seeing into the future, causing harm, or for religion. A person practicing witchcraft is called a witch, although a man practicing witchcraft is often mistakenly called a wizard (a word from Northern Europe), a warlock (a word from 14th century England), a sorcerer, or shaman (a term for people who practice magic in Siberia). Such people are said to have a knowledge of the chemical (or pharmaceutical) effects of certain herbs or shrubs. Witches can use this knowledge to help people who are sick or to hurt them.