Section 57(1) of the 1990 Act provides that, subject to the following provisions of that section, ‘planning permission is required for the carrying out of any development of land’. This planning permission may be granted following the determination of an express application for permission made to the local planning authority for the area in which the land is situated. In other cases, however, it is not necessary for an express application to be made. This is because planning permission for the development in question may have been granted by a development order, which may be a special, local, neighbourhood, or general order (such development is generally known as ‘permitted’ development), or by some other specific statutory provision (as in the case of enterprise zones or simplified planning zones), or be deemed to have been granted under other provisions of the Act (as in the case of the display of certain advertisements), or authorized by some private Act of Parliament.