There are a number of political parties in Australia. Most members of parliament belong to one of the two major parties - the Australian Labor Party and the Liberal Party of Australia. A few belong to smaller parties, such as the Australian Greens. Some members of parliament are elected as independents and do not belong to any party.
The value of political parties is that they allow coherent policies to be developed and presented to the voters in an election, and then implemented by the government. The political party with the majority of seats in the lower house of a parliament is the party that forms the government of the day. Its voting majority in parliament enables it to control the legislative process and, by enacting laws, to give effect to its policies.
The political party with the second largest number of seats in the lower house is known as the opposition. If no political party has enough seats in the lower house of parliament to form a majority in its own right, two or more political parties may join forces in a 'coalition' government. An example of this the coalition between the Liberal Party of Australia and the National Party of Australia.