There may come a time when you will be required to convert 220 volt to 110 volt and to do this you must use something known as a voltage converter. A voltage converter is a device that converts the electrical power flow and changed the electrical output of the desired power source. By far the most common use for this type of converters is to do what is mentioned before, stepping down voltage from 220 to 110 volt. However the opposite is also popular with stepping up 110 to 220 volt. It really just depends on the task at hand. Running into a problem of owning a specific electrical device that runs on a voltage you do not currently use means that you must convert the power to the correct level in order to be able to properly use it.
As mentioned before there are different items which you can use in order to get the voltage to the correct level. You must use either a step down or step up voltage converter depending on your needs. Step down voltage converters are used in order to step down the electricity in countries that use 220 volts and up. These step the electricity down to 110 volts so you can use any 110 volt electronics and appliances. The step up voltage converter does exactly the opposite and is used for the exact opposite reason. You can also buy such things as a multi step-up/step-down converter which can be used anywhere and for anything.
The type and size of voltage converter really depends on what you are planning to use it for. The particular size of a voltage converter is directly defined by the necessary wattage. So in knowing that, the size you will need will directly depend on which particular devices you will be powering and the individual number of watts each uses. Generally it is recommended that you use a voltage converter/transformer which has a wattage rating of 2 to 3 times higher than the appliance you are looking to power. This is something to look out for as certain appliances and devices such as power tools, laser printers, and even TVs require a surge of power in order to get the device running. The extra wattage needed for the surge is usually within the boundaries of a normal converter, however having it go 2-3 times higher than what you need assures there will be absolutely no problems in the future.
In the end what you actually require depends on what you are looking to power, where you come from, and where you are planning to go. You are required to do a little research in order to find out what voltage you are at currently and what voltage you will need to be at in the end. One you have figured this out you are then able to accurately buy the item you need and use it to power any one of the gadgets and appliances you are looking to power.