At the risk of sounding stupid, what exactly is a "provisional ballot"? I first thought they were like absentee ballots but apparently they are something different. Can somebody explain?
A provisional is a ballot from a person who is NOT on the voter rolls.
> what exactly is a "provisional ballot"?
It is a ballot for a vote cast with some sort of irregularity surrounding it. For example, a voter says they are registered, but there is no record of their registration. Or a voter is challenged by a poll watcher (as an imposter, etc.). In these cases, the vote is cast on a provisional ballot, which means it is set aside to be scrutinized more closely later.
If for some reason a precinct worker suspects that you're not following proper registration procedures, you're allowed to cast a provisional ballot. The provisional ballot is sealed with your name, address, etc. attached to it. They validate your registration--if you're good to go, they count it, if not, they toss it.
One legitmate use of a provisional ballot is if you request an absentee ballot, but you never received the ballot, so you decide to go vote in person. They see that you request an absentee form, and want to check that you aren't double-voting (absentee + in-person), so they have you cast a provisional ballot and check to make sure you didn't cast an absentee ballot later.