Confidence and supply
In parliamentary democracies based on the Westminster system, confidence and supply is an arrangement under which a minority government (one which does not control a majority in the legislature) receives the support of one or more parties or independent MPs on confidence votes and the state budget ("supply"). On issues other than those outlined in the confidence and supply agreement, non-government partners to the agreement are not bound to support the government on any given piece of legislation.[1][2]
A coalition government is a more formal arrangement than a confidence-and-supply agreement, in that members from junior parties (i.e., parties other than the largest) gain positions in the cabinet and ministerial roles, and are generally expected to hold the government whip on passing legislation.