Difference between avocation and vocationAvocation is an activity taken up in addition to one’s regular work or profession, usually for enjoyment; a hobby: “Her favorite avocation is reading.”
Vocation is a regular occupation, especially one for which a person is particularly suited or qualified: “I’m a carpenter by vocation, but my avocation is painting.”

Anytime someone is able to combine his or her avocation andvocation; such as, being a professor of literature and writing a novel in the spare time, is a very lucky person indeed.