Hi, thanks for your question.
Majority means more than half. Usually when the Senate or House of Representatives are voting on an idea, the idea needs the majority of senators or members to voter to support it in order for it to pass. As the Senate and the House each have a different number of parliamentarians, a majority is not the same in both chambers. In the Senate there are 76 senators, so a majority is at least 39 senators (half of 76 plus one equals 39). In the House of Representatives there are 151 members, which makes a majority at least 76 members (half of 150 plus one equals 76).
There are 2 ways to vote in the Australian Parliament; a vote on the voices and a division. Both of these votes are publically conducted in the parliament, and are recorded in the hansard record.