What type of government is formed when two or more parties join together to create a majority in a national legislature?

A coalition government is formed when two or more political parties come together to collaborate and secure a majority in the national legislature. This arrangement is typically necessary in a parliamentary system where no single party holds an outright majority, allowing diverse interests and perspectives to be represented in governance. Coalition governments can lead to more stable and representative decision-making as they often require negotiation and compromise among the allied parties, reflecting a broader spectrum of the electorate's views.

The other options represent different concepts. A majoritarian government typically refers to a system where one party makes decisions without needing to forge alliances, potentially sidelining minority viewpoints. A unitary government denotes a central authority that holds most of the power, with local governments operating under its jurisdiction, rather than a coalition of parties. Lastly, a federal government is characterized by a division of powers between a central authority and smaller political units, like states or provinces, rather than focusing on the collaborative aspect of multiple parties uniting in governance.