Can a home have both 110 volt and 220 volt power?

Answer 1

In the U.S.A., from the utility's transformer, all homes are provided with two 120 volt, alternating phases. (A phase black, B phase red) and a neutral (white) - called a single phase 3-wire system.
The neutral (white wire) allows for balance and return of the current, from and for each phase.
If one removes the neutral, this results in 240 volts, supplied by both the A phase and B phase.
For example: a plug circuit requires 120 volts. A black (A phase) and a neutral or a red (B phase) and a neutral.
An oven requires 240 volts. Both the A and B phases are supplied to the oven.
All electrical devices are required to have a grounding (green) wire, bonds the entire house to a grounding electrode.