The main function of congress is to pass laws for the union .Both houses have the power to introduce legislation on any subject except the revenue bills which must originate in the House of Representative. If it is favorably voted, then after the hereings recommendations regarding the bill are reported to the House of Representatives or the Senate by the committee. Then,The president may either sign it into a vote or veto it. If it is vetoed, Congress can override the veto by a two-thirds majority.