They belong to the seven types of taxable income and are excess income. The definition of the type of income is given in § 21 EStG. Income includes renting or leasing immovable property, in particular land, buildings and property rights (including ships).
The rental or leasing of movable property and material items (e.g. cars, machines) and the temporary transfer of rights (in particular literary and artistic copyrights). The sale of rent or lease payments can lead to income from renting and leasing. Section 21 of the Income Tax Act is to be viewed as subsidiary to other types of income, because if income from renting and leasing belongs to other types of income, it is to be assigned to them (Section 21111 Income Tax Act).