What is the difference between a bill and veto?

for a law to become legal, it must be signed by the president.... a bill is a proposed law submitted for approval by the president by both houses of congress (senate and the house of representatives)... a veto is the presidential prerogative not to approve the law if he is contrary to it. if that is the case, it is then returned back to the congress for more deliberations and re-submitted to the president for approval. if he vetoes it again, i think congress can pass the law by two-thirds majority... if the bill becomes a law and it turned out to be disadvantageous to the people, it is congress who gets blamed and not the president for letting it become a law...