What is a it called where one company controls all called?

I was giving some thought to it and I thought I heard somewhere (in fiction) of states where one company controls most of the country/state and has a total monopoly over it. Thanks.What is a it called where one company controls all called?
One party states, like the Bolchevique in Communist Russia fall in the description you provided.


Hope it helped.What is a it called where one company controls all called?
An atrocity.
cornering the market