When a bill is introduced in the Senate, it first goes to a committee for review and debate, where it can be amended or changed. If the committee approves the bill, it's then sent to the full Senate for a vote. If the Senate passes the bill, it's sent to the House of Representatives, where it goes through a similar process of committee review and debate, and then a vote. If the House passes the bill, but makes changes, it's sent back to the Senate for approval. Once both the Senate and House agree on the bill, it's sent to the President to be signed into law, although the President can veto the bill, in which case Congress can try to override the veto with a two-thirds majority vote.