I want to ask how can we get 110V and 220V in our homes in Saudi Arabia

Or in other words
what is the wires that inters our home ????
I heared in this group about 120 and 0 and -120 and, but these are DC
and we get AC in our home and according to my knolage in AC we dont
have negative or positive because this is an altranating current .
PLEASE ANSWER ME WITH A CLEARE EXPLANATION
THANK YOU....................................