This may sound simple, but I am confused. Do I need a converter to charge my samsung galaxy 4 phone in Europe or is an adapter enough?
A converter is an electronic device that converts voltage, for instance, 230V in Europe to 120V for US devices. But the charger for your Samsung device accepts a range of voltages from 100V to 240V (and probably outside that range). So you Samsung charge will accept 230V in the EU.
However, your two-blade US plug will not fit into the round holes of a continental Europn receptacle (or into a UK one, either). For that you need a plug adapter, which is a passive mechanical device that fits into the European receptacle and accepts American plugs.
Or, I could say yes, because the Samsung charger you already have is a voltage converter. It converts input voltages of 100VAC - 240VAC to 5 VDC.
If you see a range of voltages printed on the item or its plug (such
as "110–220"), you're OK in Europe. Some older appliances have a
voltage switch marked 110 (US) and 220 (Europe) — switch it to 220 as