Answer: • While both open and closed primaries are designed to narrow down the choice of candidates of a party, to stand in the next general elections against the nominee of the other party, anyone can take part in an open primary irrespective of his party affiliations.
• On the other hand, only registered members of a political party can take part in a closed primary.
• There are states with open primaries while there are many states where only closed primaries are held.
Explanation: Closed primaries: There are many states where closed primaries are held. These are elections within the party to narrow down the choice of candidates for the general elections where the winning party candidate fights against the nominee of the other party. The distinguishing feature of a closed primary is that only those who are registered members of a party are allowed to take part in these elections. A voter has to state his preference for the party before he is asked to vote in the primary. You are denied permission to vote in the closed primary of a party if you are not a member of that party.
Open primaries: Open primary is a ballot open to people with all affiliations. Thus, whether you are a Republican, a Democrat, a Libertarian, or even a communist, you have the right to vote in the primary election of any party you desire. This means that if it is the Republican party that is deciding upon its candidate, to fight in the next general elections for a particular position or seat, you can indicate your preference no matter whether you are a registered Republican or not.