A more thorough explanation:

A representation election is an election held by the National Labor Relations Board to determine whether a particular union will represent employees in a bargaining unit. This type of election is used to decide which union will be the exclusive representative of the employees in collective bargaining negotiations with their employer.

For example, if a group of employees at a factory want to form a union, they may petition the National Labor Relations Board to hold a representation election. The election would then be held to determine whether the employees want the union to represent them in collective bargaining negotiations with their employer.

Another example of a representation election is when a union wants to replace an existing union as the exclusive representative of a group of employees. In this case, the National Labor Relations Board would hold an election to determine whether the employees want to be represented by the new union or continue to be represented by the existing union.