AC power allows the variation of voltage levels via a transformer, unfortunately this doesn't work with DC power. Sometimes it is necessary to convert the power, for example, from a 24V truck battery to 12V in order to power a car radio. So it's necessary to use a converter to drop the power and make it safe for the device.
A wide variety of types are available to suit different needs. Some DC-DC converters will step up the power, others will step down and some can do either. It's important to know the specifications of the converters being used to avoid damaging equipment. Types of DC-DC converters include:
Advantages of DC-DC converters
Driving a device by increasing or decreasing the available input voltage prevents damage or breakdown. Battery space can also be reduced.
Isolated DC-DC converters are safer to use in cases of internal failure as they prevent the input voltage from being transmitted to the output.