CITES works by subjecting international trade in specimens of selected species to certain controls. All import, export, re-export and introduction from the sea of species covered by the Convention has to be authorized through a licensing system. Each Party to the Convention must designate one or more Management Authorities in charge of administering that licensing system and one or more Scientific Authorities to advise them on the effects of trade on the status of the species.
The species covered by CITES are listed in three Appendices, according to the degree of protection they need. (For additional information on the number and type of species covered by the Convention go to https://www.cites.org/eng/disc/how.php)