Final answer:
An open primary allows voters to select which party's primary they wish to participate in on the day of the election; they can only vote in one party's primary. A closed primary allows only registered party members to vote in the party's primary election. A blanket primary is not widely used in the United States. This type of primary allows voters to participate in all party's primary elections by putting them on one ballot.
Step-by-step explanation:
An open primary allows voters to select which party's primary they wish to participate in on the day of the election; they can only vote in one party's primary. A closed primary allows only registered party members to vote in the party's primary election. A blanket primary is not widely used in the United States. This type of primary allows voters to participate in all party's primary elections by putting them on one ballot.