National standard, American standard, European standard, Australian standard, British standard of these socket standards how to distinguish?

In addition to the different appearance of the socket, the countries of the alternating current (mains) voltage is different, China and many countries is 220V some countries are 110V, so you need to pay attention to some of these countries in the purchase of electrical appliances or to go to these countries before you want to understand clearly, you can prepare to convert the transformer. In addition, there is now a universal socket converter, better to use, is not connected to high-power appliances, general digital products, small appliances are very suitable.