The purpose of this paper is to present the various forms (administrative, political and fiscal) and the various types (deconcentration, delegation, devolution) of decentralization. We highlight the strength and weaknesses of these various forms of decentralisation, as well as examine the specific aspects of their implementation. We divide this text into three sections, based on the following questions : “What is decentralisation?”, “How do we choose the type of decentralisation we want?” and “How do we manage decentralisation?”