A parliamentary system of government is characterized by the fusion of the legislative and executive branches, where the executive derived its authority from the legislature. In this system, the prime minister is typically the head of government and is accountable to the parliament, often requiring the support of a majority to govern effectively. This structure allows for more efficient law-making, as the executive can enact policy proposals with support from the leading party or coalition. However, it can also lead to instability if coalition governments fail to maintain consensus.