People are using “converter” and “adapter” without appreciating the difference. An adapter has different prongs that fit the different plug sockets. A converter has the prongs but also takes European 220V and outputs 110V (typically these can cost more but that is not always the case). However that is completely unnecessary for modern electronic devices since they are compatible with both voltages.
I travel to Europe at least 4-5 times a year and just take an adapter (but then I don’t use a travel iron or hair dryer).