Almost all of them have European surnames, but only ~20% of them have a European ancestor. If you are white, chances are good one of your ancestors came from France, or used a French surname to fool the authorities.
1 AC, or alternating current means the electrical current is alternating directions in a repetitive pattern.  AC is created by generators in power plants, and other sources. This AC current is delivered to our homes and businesses by the power lines we see everywhere.
The main difference between the two is in how the current flows. Direct current, commonly abbreviated as DC, flows uniformly in one direction while alternating current, also commonly abbreviated as AC, changes direction at a given rate or frequency. The main consequence of this is the polarity of the voltage.