Interesting question! All decisions of the Australian Parliament, in both the Senate and the House of Representatives, begin as motions. A motion is a formal proposal made by a senator or member asking the Senate or House to take action of some kind. Decisions are made by agreeing to a motion. For example, the Senate and House the pass bills—proposed laws—by agreeing to a series of motions. Motions are used to refer matters to a committee for investigation or to seek the support of the Senate or House for an issue.
In order for a motion to be considered in the House of Represented, a member must move the motion and usually another member must second it. The Speaker then puts the motion—question—to the House, which debates and votes on the question. If the House agrees to the motion, then all members of the House must accept that decision. A similar procedure is followed in the Senate.
To find out more about motions, check chapter 10 of the Standing Orders—rules—of the House of Representatives and chapters 13 and 14 of the Standing Orders of the Senate.