When you are thinking about internships, two are the main concepts to keep in mind: activation and (credit) recognition.
To activate an internship means to sign a written agreement that will be the contractual basis of the experience. Without this agreement, the internship formally does not exist; this means that you have to activate it before the beginning of the experience.
To recognize an internships means having it registered in your study plan and getting credits for it.
An internship that has not been properly activated (and that therefore formally does not exist) cannot be recognized and grant credits.
In order to be recognized and internship have to comply with the duration, timing, content and hosting employer requirements specific for the degree course.
The recognition procedure is managed through JobGate and usually follow these steps: the advance authorization, a formal evaluation at the end of the internship and the final validation by the degree course director or his/her delegate.
Different experiences can follow slightly different procedure (e.g. a report on the research activity is required for fields projects).