Presidential vetoes serve as a crucial check in the legislative process, empowering the president to reject legislation passed by Congress. When a bill reaches the president's desk, they can either sign it into law or issue a veto. A vetoed bill can only become law if Congress overrides it with a two-thirds majority vote in both the House and Senate. This power ensures that the president can block legislation deemed harmful or counterproductive. Additionally, the threat of a veto encourages lawmakers to consider the executive's stance while drafting legislation, fostering greater collaboration between branches of government.