The advantages of multi-party system are:
(i) Since, plurality of ideas and opinions is the essence of democracy, there must be a multi-party system. As this system allows a variety of interests and opinions to enjoy political representation.
(ii) Under this system, the choice of the voter is not limited to two candidates only. It gives a voter enough scope to make intelligent choice.
In the following ways, alliance is different from coalition
Alliance : When several parties join hands for the purpose of contesting elections, it is called an alliance or a front, e.g. the National Democratic Alliance.
Coalition : When no single party gets a majority in the election and the government is formed by two or more parties coming together, it is referred to as a coalition.