Labor is one of the two major parties in Australian politics and the current party in power. They are slightly leftist and the opposition is the Liberal party, which has nothing to do with being liberal as a person, and they are the right wing party, like the Republicans. Whoever leads the Labor party is the one who runs the country--the Prime Minister. So the previous leader, Julia Gillard, was Prime Minister and then she called a vote to make sure she was still the leader. The leader of each party is determined by the party, not the people. The people vote for the party. Julia Gillard was voted out by the party and replaced by Kevin Rudd, who was PM prior to Ms. Gillard, who ousted him before the end of his term, just as he did to her a few weeks ago.