Assuming you read the article, the difference is that they have two hot prongs instead of a single hot pong. The 4-prong outlets, like a standard dryer outlet, allow a device to use both 120v and 240v. Sometimes appliances take advantage of this by using a 240v heating coil and a 120v motor.
Adopting EU-style plugs is more problematic. There's the two hot prong problem, instead of one hot and one neutral. The other problem is frequency, as we use 60hz instead of 50hz.
EU-plugs don't treat hot and neutral side differently at all, it's just a convention and in practice it doesn't matter when they are reversed, it does happen often. Only the earth must be always correctly connected. It would work fine with two hot prongs too.
Assuming you read the article, the difference is that they have two hot prongs instead of a single hot pong. The 4-prong outlets, like a standard dryer outlet, allow a device to use both 120v and 240v. Sometimes appliances take advantage of this by using a 240v heating coil and a 120v motor.
Adopting EU-style plugs is more problematic. There's the two hot prong problem, instead of one hot and one neutral. The other problem is frequency, as we use 60hz instead of 50hz.