We use the power outlet are mostly single-phase three-wire socket or single-phase two-wire socket
AC wire strikes zero line then it does not affect the use of electrical appliances.
The following two lines are the neutral line (the sign letter is "N" Neutral wire), FireWire (logo letter "L" Live Wire), the order is left and right fire, (the back of the plug against himself).
Three plugs are positive three-shaped arrangement, which the longest and thickest copper plug is the ground (Earth wire), the ground has a special grounding symbol.
Where the shell is a metal household appliances are used in single-phase three-wire power plug
