In administrative law, it is all about the conflict between citizen and state. Usually, an administrative decision is challenged – for example, the exmatriculation decision of a university, the withdrawal of the driving license by the administrative authority, the denial of a building permission, a police action or a decision of the municipal council. This burdens the addressee with the obligation to go to court himself, he cannot simply wait for the state to act.
Since the state is fully and directly bound by the constitution, fundamental rights must be taken into account at every stage of the process. After (unsuccessful) completion of the legal process, however, the question arises as to whether the fundamental rights were also correctly applied. This can be checked upon by a constitutional complaint.