Let's say it's the proportion. Maybe it's the proportion that will vote for a candidate. We can't survey everyone, so we take a sample. And from that sample, maybe we calculate a sample proportion. And then using this sample proportion, we calculate a confidence interval on either side of that sample proportion. And what we know is that if we do this many, many, many times, every time we do it, we are very likely to have a different sample proportion. So that'd be sample proportion one, sample proportion two.