A tax law typically emanates from a public bill that is proposed by a member of the legislative body, usually a member of the government or a member of the opposition party. The bill must go through several stages of review and debate in both houses of the legislative body, and amendments may be made to the original proposal.
Once the bill has been passed by both houses of the legislative body, it is sent to the executive, which is usually the President or the Prime Minister, for their signature. The executive may either sign the bill into law or veto it, in which case it must go back to the legislative body for further review and potential revision.
It is worth noting that tax laws can also be proposed by the executive, but they must still go through the same process of review and debate in the legislative body before they can be passed into law. In general, tax laws are intended to raise revenue for the government, and they may be used to fund various programs, projects, and services.