Electronic voting in the United States involves several types of machines: touchscreens for voters to mark choices, scanners to read paper ballots, scanners to verify signatures on envelopes of absentee ballots, and web servers to display tallies to the public. Aside from voting, there are also computer systems to maintain voter registrations and display these electoral rolls to polling place staff. Most election offices handle thousands of ballots, with an average of 17 contests per ballot, so machine-counting can be faster and less expensive than hand-counting.