A politician is a person involved in politics. A current politician does necessarily hold a position, and can e.g. just work in information and information collection, revising law-documents or collecting funding. A politician will most typically be involved in a political party.
A diplomat is officially appointed by a state or organisation to oficially represent this state or organisation in different kinds of negotiations and protection of interests. Diplomats are expected to be neutral and not show party favoritism. <span />
