Because the standard voltage in South Korea (220 V) is greater than in the United States of America, you cannot use your electric equipment without a voltage converter (120 V). An electronic voltage converter can be bought at electrical shops or online. It usually costs less than $100.
Electrical power in South Korea is provided by two polarized wires called "hot" and "neutral", which are always white or grey. The term "ground" means the third wire which is used to connect metal objects together. In American systems, hot and neutral are separated but have the same potential, while ground is separate from both hot and neutral. Electricity flows on hot to the next thing that needs power, then returns on neutral to the originator of the current, whether it's another appliance or the wall socket. A device called a "breaker" decides which circuit will get the power at any given moment. In America, breakers must be used with electricity meters that measure usage during each cycle of AC power. These meters need to be set to measure time-of-day rates, so they won't charge you for sleeping appliances like TVs and stereos when you're not using them.
In general, if you can turn on your equipment by pushing a button, then it's easy enough for Americans to use.
Electric Plug Type in South Korea The South Korean voltage is a standard 220V at 60Hz when using the two circular pins with no earth pin. Fortunately, the Korean electrical outlet only accepts one type of plug, so you can charge your electronics all around the nation with a single Korea power converter. Some laptops and other electric devices may need an adapter or transformer to be able to use the local power supply.
In addition, most hotels in Korea have free wired Internet access, so you don't need to bring your own device for that purpose. However, many public libraries do not have computers available for loan, so check before you go to make sure that there are no requirements for checking out computers. Computers are often located in the children's section or on a first-come, first-served basis, so it's best to arrive early in order to be able to use one if needed.
Finally, batteries require regular charging, which can be time-consuming in some countries, but the facilities are usually available at hotel rooms and restaurants across the country.
You can use your electric appliances in South Africa if your country's standard voltage is between 220 and 240 V. (as is in the UK, Europe, Australia, and most of Asia and Africa). A combination power plug adapter and voltage converter is another option. They are available at electrical supply shops everywhere and usually cost about $10-$20.
Electrical outlets in South Africa have two round pins rather than three flat pins, so an appliance that requires three flat pins will not work here. Also note that some appliances such as hair dryers, irons, and electric knives have been known to damage homes by too high of a voltage when plugged into a socket designed for low-voltage appliances. So make sure you don't overload these types of appliances.
In general, if you can use it in the US, you can use it in South Africa. However, local standards may be different from American standards. For example, hot tubs require 120 volts but not always in combination with a ground wire. In this case, you would need a transformer to connect your house circuit to the pump. The water heater is another example; many heat pumps operate on 115 volts while most heaters need 180 volts. Again, check with local authorities before bringing such items into South Africa.