What is the difference between the promoter and the advisor? I am applying for a Ph.D. position at Netherlands and I see that there will be a promoter and an advisor. I have never seen such a title as "promoter". What is the difference between the two titles?
As far as I understand, in the Netherlands, only full professors may be appointed "promoter", i.e. the official advisor, the super-boss if you will. Other faculty members must apparently get authorization from the university (see comment).

So if you are going to be supervised by someone who is not full professor (e.g. associate/assistant professor), that person will be appointed as "(co)advisor", while a full professor will be acting as an official advisor/promoter and will chair the doctoral examination committee.