European power outlets generally have two round prongs and operate at 220-240 volts, which is different from many other regions. A travel adapter typically has a universal input that accepts plugs from different countries, and a European output that fits into the power outlet. Some travel adapters also offer additional features, such as built-in surge protection, compatibility with different types of devices, or multiple USB ports for charging devices. It's essential to note that a travel adapter only changes the plug shape and not the voltage, so if your device does not support 220-240 volts, you will also need a voltage converter to avoid damage to your device.