The processor of personal data is a natural or legal person, public authority, agency or other entity that processes personal data on behalf of the controller. The processor differs from the controller in that, as part of the activity for the controller, he may perform only such processing operations which the controller entrusts to him or result from the activity for which the processor has been authorized by the controller.
It must be said that the processor is only a processor in relation to the personal data provided by the controller, not the personal data it processes for purposes that directly affect it (eg it is the controller in the processing of personal data of its own employees).