A product that can use both 110V and 220V voltage like a laptop adapter is generally referred to as:

• Dual voltage adapter (dual voltage adapter)

• Universal voltage adapter (universal voltage adapter)

• 100-240V compatible power adapter (100-240V compatible power adapter)

• Or simply referred to as "worldwide voltage" or "auto-voltage" adapter.

The product label usually states something like: Input: 100-240V ~ 50/60Hz

This means it can automatically recognize and operate in most voltage environments around the world.

One of the things we often forget when traveling abroad is the difference in outlet shapes and voltages.

Especially for those bringing electronic devices like laptops, mobile phones, and electric shavers, this is an important aspect to be aware of. It's not just about the plug not fitting; the difference in voltage can cause the device itself to break, which is a significant issue.

According to U.S. standards  when traveling to Mexico, Canada, Europe, or Korea, I will easily summarize how to prepare adapters or plugs.

The U.S., Canada, and Mexico use the same Type A/B

The 110-120V voltage / Type A, B plugs used in the U.S. are almost identical in Canada and Mexico.

• The plug shape has two flat pins (Type A), or a third grounding pin next to it (Type B)

• The voltage is also the same at 110-120V

This means that you can bring electronic devices used in the U.S. without any issues. Even hair dryers and electric kettles will work just fine. No additional adapter is needed.

Europe uses completely different Type C, E, F + voltage caution

Most European countries use 220-240V voltage, and Type C or F plugs.

• The plug shape has two round pins (Type C, F)

• Most are the same in France, Germany, Italy, Spain, etc.

• The UK is an exception with three flat pins (Type G)

The problem is the voltage. Most U.S. products are designed for 110V, while Europe uses 220V. Nowadays, most laptops and phone chargers are compatible with 100-240V, so that's fine, but hair tools or shavers can break.

So when going to Europe:

• Make sure to bring a plug shape converter adapter

• Check if the device has automatic voltage conversion. (If the product label says "Input: 100-240V", it is automatically compatible)

Korea uses Type C/F but has the same voltage as Europe

Korea also uses 220V voltage like Europe, and Type C or F plugs.

• The plugs are almost identical to Europe (two round pins)

• You cannot plug in U.S. products directly; a converter adapter is needed

• Because the voltage is different, you must check if the device supports 100-240V.

In other words, you can think of Korea as being the same as Europe, but it doesn't have special plugs like the UK, making it a bit more convenient.

In Korea, converter plugs can be easily purchased at supermarkets or airports.