A midterm election
Those are commonly known as mid-term elections.
Primary elections or primaries is what these elections are called.
In the US the elections are called primaries as they are the first step to the election of the final candidate. In the presidential elections Barack Obama first had to beat Hillary Clinton among others before facing John McCain who had beaten other candidates from the Republican party.
Presidential Elections
It's the day when elections are held (and the name The Day When Elections Are Held was too long).
The practice of moving presidential primary elections to the early part of a campaign is called front-loading. It involves states scheduling their primaries or caucuses earlier in the election calendar to have a greater influence on the nomination process and attract more attention from candidates and the media.
it is called a general election unless we are voting for a president then it is called a presidential election
The President-Elect.
Primary
The three types of elections in Arizona are primary elections, general elections, and special elections. Primary elections are held to select party candidates for the general election. General elections determine who will hold office. Special elections are called to fill vacant offices or vote on specific issues outside the regular election cycle.
An election held to choose candidates for the main election is called a Primary Election.
caucus_nominating convention_primary