The only constitutional responsibility of the vice president is to preside over the Senate. He or she does so by standing at the presiding officer's desk located on the Senate Floor.
Even though the vice president presides over the Senate, he or she does not have the right to vote in the Senate except to break a tie. The vice president does not address the Senate either. The initial role of the vice president was to appoint senators to standing committees and regulate access to galleries, but these duties were removed in the 20th century. The role of the vice president is more executive nowadays, and he or she usually presides over the Senate on ceremonial occasions.