A Frequency Converter (or Frequency Changer) is a device that converts a current with one frequency to a current with another frequency. Frequency converters are usually used for speed regulation of motors (for example, in fans and pumps, often in industrial applications). It's wise to investigate whether a frequency converter can be used with the device on which you require frequency conversion to ensure it is safe to do so. Additionally, frequency converters can be costly, so it's worth doing plenty of research before committing to purchase one.
Unless specified by the manufacturer to operate on both 50 and 60Hz, electrical devices may not operate efficiently or even safely if used on anything other than the intended frequency. However, most equipment is not noticeably affected by differencies in frequencies. Some exceptions are:
You should check whether multiple frequencies are supported by your device. If not, check the device's manual and do some research to determine whether a frequency converter can be used with the device.