Major American presidential appointments and treaties must be approved by the United States Senate. The U.S. Constitution gives the Senate the final say in both of these matters.
There is a crucial difference in the senatorial approval process for presidential appointments and treaties. A presidential appointee only needs a majority vote to be confirmed. By contrast, a treaty needs a two-thirds majority to become law.
Another difference is that only the most important appointments, such as Supreme Court justices, cabinet officers and ambassadors, are generally approved by the Senate. Lesser officials are simply selected by the President or various department heads, in most cases. All treaties, however, must receive senatorial approval.