A two-party system is a system where two major political parties dominate voting nearly all elections at every level of government.
As a result, all, Or nearly all, elected offices are members of one of the two major parties. Under a two-party system, one of the two parties typically holds a majority in the legislature and is usually referred to as the majority, party while the other is the minority party.
While the term two-party system is somewhat imprecise and has been used in different countries to mean different things, there is considerable agreement that a system is considered to be of a two-party nature when election results show consistently that all or nearly all elected officials belong to only one of the two major parties, such as in the United States.
In these cases, the chances for third party candidates winning election to any office are remote, although it’s possible for groups within the larger parties, or in opposition to one or both of there, to exert influence on the two major parties.