Snapshots are a way to see how exactly your campaign is progressing, how many votes you or your candidate may garner, what percentage of the vote may be won and how all this breaks down in various ways,

Each voter in the system is assigned a "voting probability" (how likely a person is to vote), and a "support probability" (how likely somebody will vote for you or your candidate.) As your campaign reaches more people, and these probabilities are adjusted, the snapshots should become more and more accurate...think of snapshots as your own public opinion survey.

As a very simplistic example, imagine an election with only 4000 voters as shown in the table below. Each voter is assigned a voting probability (VP) and support probability (SP) which are adjusted over time as your campaign team comes into contact with them. Originally everybody given a 20% likelihood of voting, and a 20% probability of voting for you.

For the purposes of this explanation, I've grouped our votes into 4 groups of 1000, each group sharing the same voting and support probabilities. In reality, each individual voter would be counted seperately. We just want the numbers to be large enough