AC

1. Short for Alternating Current, AC is an electrical current that reverses or alternates its direction of flow. On May 1, 1988, Nikola Tesla patented the rotating field motor and later sold the rights to George Westinghouse. This invention helped create and transmit AC power, and today is still the method for generating and distributing AC power.
   
   AC power has many advantages over DC including the ability in transmitting power easily and effectively and allows for basic electric devices to be made easily.
   
   A normal wall outlet in the United States is 110 volts transmitting currents at 60 hertz per second. European power systems use 220 volts alternating current at 50 Hz.
   
   
2. Short for Anonymous Coward, AC is commonly used in message boards and newsgroups for users who do not wish to divulge their identity.
3. Short for Asheron's Call, AC is a name of a MMORPG developed by Microsoft.

Also see: DC, Impedance, Power definitions