Definition of Political Parties:
A political party is defined as an organised group of people with at least roughly similar political aims and opinions, that seeks to influence public policy by getting its candidates elected to public office.

The purpose of political parties is for each state and territory to have full opportunities for their states/ territories say.

"a coalition between Liberals and Conservatives"

An example of this is when the Liberal Party forms a coalition with The Nation Party because

-they both are towards different aims
-they are political rivals

a temporary alliance for combined action, especially of political parties forming a government.

Coalition

In Australia government is formed in the House of Representatives, there are also members of the government from the House of Senate. The government may or may not hold majority of seats in the Senate.