In order to carry out the tasks and achieve the objectives accordance with their competences, public administration authorities use not only administrative acts, which have a unilateral character, but also contracts, which are bilateral administrative acts, in particular because they are subject to public law rules and are part of the administrative law regime. The administrative contract is a contract concluded by the public authority, by virtue of the prerogatives of public power, having as its object the administration and use of public property, the execution of works of public interest, the provision of public services, the activity of civil servants, arising from the service relationships regulated by their legal status.