Coalition government, is actually group of advisors formed when different political parties unite in the supervision and regulation of a country. We can call it a temporary association, which is formed when no single political party gains a clear majority and as a substitute competing parties negotiate to work together. Such situations usually happen during crisis period, like war, or a political breakdown. Members of all parties in a coalition government are appointed to a cabinet. Cabinets based on a group of parties that command a majority in parliament tend to be more stable and long-lived than minority cabinets. While the former are prone to internal struggles, they have less reason to fear votes of no confidence. Majority governments based on a single party are typically even more stable, as long as their majority can be maintained.
In our country, the very first every successful coalition administration that completed the entire 5-year term (1999 to 2004) was the Bharatiya Janata Party (BJP) led National Democratic Alliance (NDA) with Atal Bihari Vajpayee as Prime Minister. There is one more talked about a coalition, Congress-led United Progressive Alliance (UPA), consisting of 13 separate parties ruled from 2004 to 2014 (two terms) with Manmohan Singh as Prime Minister.