Hi, thanks for your question.
If the Senate is considering a bill, but the majority of senators don’t like the bill, the Senate has a few options. It can vote on whether the bill should be passed, in which case the bill will not be agreed by the Senate, and the bill will not become a law. The Senate can consider making changes to the bill (called amendments) in order to improve the bill, The changed bill might gain the support of the majority of senators. If the Senate wants to learn more about the bill it could send it to a Senate committee to research the bill. The committee will report to the Senate and suggest whether the bill should be agreed to, not agreed to, or changed.
If the Senate does not agreed to a bill, it does not become a law. However, the bill can be re-introduced to the Senate. If the Senate does not agree a second time to a bill which has been passed by the House of Representatives, it could possibly become a trigger for a double dissolution.