Voltage in the EU is 240 volts vs 120 volts in the US. Most current devices (laptops, USB charging blocks, game systems like a Nintendo Switch) have multi voltage capability. Here is a pic of my laptop cord/adapter. Look for "Input Voltage" and see if it shows a range. This one is 100-240 volts. My Nintendo devices all say 100-240.
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You will need an adapter for the plug end to fit in the european outlets, but not a "converter" that changes the 240 volts down to 120.
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