The majority voted to pass the bill through the House of Representatives, which means it will now be sent to the Senate for our Senators to decide whether they agree that it should become law.
In parliamentary jargon, our Members of Parliament (MPs) voted to give the bill a third reading.
What does this bill do?
The purpose of this bill is to make it possible for the government to hold a national plebiscite to ask Australians "Should the law be changed to allow same-sex couples to marry?"
What is a national plebiscite?
The bills digest explains that:
a national plebiscite is a vote by citizens on any subject of national significance but which does not affect the Constitution. Plebiscites are normally advisory and do not compel a government to act on the outcome. There have only been three national plebiscites—two on conscription during World War I (both defeated) and one on the choice of a National Song in 1977.
Why don't some supporters of marriage equality support this bill?
Several parties and independents oppose this bill for two main reasons: cost and concern that a plebiscite could harm members of the LGBTI community.
So, what next?
The bill will be sent to the Senate. However, since the Labor Party has agreed to vote against it alongside the Greens, the Nick Xenophon Team and Derryn Hinch, it will not pass and so will not become law.
ABC News gives a neat summary of the situation and what may happen next.