A bill does not become law until it is passed by the legislature and, in most cases, approved by the executive. Once a bill has been enacted into law, it is called an act of the legislature, or a statute. 

A bill is a proposed law that is formally written and submitted for discussion. Before it becomes a law, it must go through several readings, debates and approvals in the legislative arm of government. The executive may initiate or implement laws, but it is not the primary body for considering a bill.