Germany is divided into 401 administrative districts. There are 294 rural districts (German: Landkreise), listed here. There are also 107 urban districts (Kreisfreie Städte / Stadtkreise) listed in List of German urban districts.
Urban districts are large towns or cities which handle their own local government. Rural districts provide services for the smaller towns and villages in an area. In some states the towns and villages in a district are joined into ämter (although "amt" is not always the name used). This is because the towns and villages in the area are too small to provide the local services (for example fire brigade or cemeteries). If the "Amt" system is used towns or settlements might be "amtfrei" that is, not part of an amt because the town can handle its own local affairs.
In some states there is another level of government, the Regierungsbezirk or governmental district. Several urban and rural districts are joined to make a regierungsbezirk, which does some of their jobs, especially things like land-use planning which can affect several districts.