VEP and VAP are essential statistics to political elections. VEP stands for the voting-eligible population. It represents the number of people that are eligible to vote. The name doesn't include those who are felons or are outside of the United States. VAP stands for the voting-age population.
It is a broader population compared to VEP. If one is over eighteen and a resident of the United States, they will be counted into the VAP. Unlike VEP, VAP will include those who have felonies and those who are in the United States but haven't become citizens. It also includes people who haven't registered to vote yet.