Approval is the result of successfully completing the quality assurance process under which a VTS training course is assessed to ensure that the IALA standards are met.
In these Guidelines, the Accreditation process is for the VTS training organization and Approval is for the actual VTS courses themselves.
Source: IALA Guideline 1014 para. 2
Vessel Traffic Services
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM