240V split phase and 240V single phase
The power feed to a North American residence is normally provided by a center-tapped transformer, with the center tap of the transformer secondary grounded.  the full secondary winding produces 240 Volts.

the connection is like so:







simulate this circuit &ndash; Schematic created using CircuitLab

Arghhh!  The shcematic editor won't let me draw what I want!

The two ends or the transformer winding (120 V A and 120 V B) are each 120 Volts from Neutral, but 180 degrees out-of-phase, so you get 240 volts between them.

Most outlets in a home will connect between 120 V A and Neutral, or between 120 V B and neutral, so will get 120 volts.

Certain heavy loads (electric stove, electric water heater, electric clothes dryer) will connect between 120 V A and 120 V B to get 240 volts.