Municipal districts exist only for Paris, Lyon and Marseille. The goal of the policy that involved decentralising administrative services in 1982 consisted of bringing municipal administrations closer to their citizens and of devolving the management of the three largest municipalities without altering their unity. This devolution was performed by giving certain powers to a council and an elected mayor. These districts and their council coexist with a municipal council that maintains the city's communal unity.
Do not confuse the municipal district, the partition of 3 main French cities, with the district, a subdivision of the department