A provisional government was a temporary form of government which served as a political transition to the next.
After the Cardassian withdrawal of the Occupation of Bajor in 2369, and the cessation of the Bajoran Occupational Government, one of the first steps to recovery for the planet was the formation of the Bajoran Provisional Government which eventually became the Bajoran Republic. (DS9: "Emissary", "Duet", et al.)