You might not think about it every day, but when you plug things into power outlets in your house, you're using a form of electricity called alternating current, or AC.
In your car, on the other hand, every time you listen to the radio, or charge your smartphone via the 12v charger, you're using direct current, or DC.
There is a difference between the two. One current type has a one-way direction of travel (DC), while the other current type has a two-way direction of travel (AC).
It is possible to convert between the two, but doing so is incredibly inefficient, which is why certain electronics are made for the application that they'll be used for. For example, since your house is set up for AC, your appliances will be made to be compatible with AC. Likewise, since your car is set up for DC, your car accessories are made to be compatible with DC.
In this video, you'll get to see some awesome demonstrations of AC and DC current and learn more about the properties of electricity.