Our debate is upon the meaning of the notions of fantasy and the fantastic. Scholars sometimes use both terms as synonyms, but on other occasions in order to distinguish between genres or types of discourse depending on the context or, on their purpose. The consequence is a wide range of definitions and notions that sometimes become useless or hard to understand. After explaining this confusion, we would like to investigate several approaches of the genre, mode or discourse of fantasy. The aim is to find an appropriate theoretical approach, for the variety of texts and contexts in which we may speak about fantasy.